5 mm post

Weapons for everybody!

One of the simplest innovations in Transformers toys, using universally sized posts for accessories, weapons and figures is something that has characterised several Transformers lines throughout the years. The most common universal post and port size is the 5 millimetre (5 mm) post (also commonly stylized without a space as 5mm post in defiance of SI standards). This size was used throughout Generation 1, Generation 2, and almost universally throughout Armada, Energon, and Cybertron.

Using a single, universal size of weapon post allows Transformers toys to swap weapons between one another. During most Transformers toy lines, this interchangeability was seldom advertised as a feature of the toys, but during Armada, that changed. The introduction of the Mini-Cons gave 5 mm posts an entirely new purpose: A hollow 5 mm post could now become a mounting point for a Mini-Con. The interchangeability suddenly became an advertised feature of the toys.

The 5 mm post has become pretty ubiquitous in Transformers toy design, with only a few lines (mainly the 2007 live-action movie and Animated) favoring less-interchangeable systems.

Functionality

Backwards compatibility

"Dude, you're right. Guns with their posts in the right place rock!"

Probably the biggest, most meaningful aspect of using a universal fist size is compatibility between toys. You can share your accessories or Mini-Cons or even some integral parts of toys around to other toys from the same line. Even better for long-term fans of the franchise is that the continuous use of 5 mm posts from Generation 1 onwards into modern lines means that toys are actually backwards-compatible with the accessories from older toys. As well as delightful opportunities for mixing and matching, this means that characters who get new toys can use accessories from their old toys. Even if you don't like "Classics" Optimus Prime's rifle, you can always just give him Powermaster Optimus Prime's rifle, or Star Convoy's.

This compatibility works both ways, allowing you to use Armada, Energon and even Power Core Combiners weapons with old Micromaster Bases or Headmasters toys.

A matter of tolerance

Despite the fact that 5 mm posts are supposed to be universally the same size, this isn't always the case. Sometimes, due to play wear or simply to slight (very slight) differences in tooling, some posts are tighter or looser than others. This can mean that sometimes a toy will hold a gun loosely, or that a weapon will be too tight to fit into another toy's hand.

Generally, this is only a problem on toys or toolings that have seen a lot of use. A Generation 1 toy like Soundwave that was produced for several years and re-released many times might actually show a difference in tolerance between different samples of the toy. Similarly, toolings which see a lot of use, such as "Classics" Starscream, can begin to show mould wear. There are many reports of later Henkei! Henkei! versions of the mould not being able to hold their weapons correctly because tolerances are poor. There are several recommended actions for fixing loose sockets, such as floor polish.

If a toy sees a lot of play, especially if weapons are being removed and replaced repeatedly, a hole (or sometimes a post) can wear down, making the weapons looser. It's possible to increase this problem while swapping weapons between different toys. If a gun post from a Pretender Bumblebee is slightly smaller than the post from Pretender Grimlock, then Grimlock's gun might actually stretch Bumblebee's fists. This could result in Bumblebee no longer being able to hold his own gun firmly. It's advisable when swapping guns between different toys to be aware of the slight differences in tolerances between toys.

Additionally, different ports and posts on the same toy may have different tolerances. Sometimes this is to prevent accessories from being inserted somewhere that could result in damage, such as Shockwave's Leader-class Siege figure; the post on the end of his hose is slightly bigger than most of his ports, except for the ones that are pointed out in the instructions for transformation. However, other times it appears to be a mistake - the same figure has difficulty plugging in accessories from other figures such as Weaponizer parts due to the ports being shrunk to prevent the hose from being inserted somewhere it could be potentially overextended.

Multiple posts and double posting

"Pssst—hey, bud!"
"WHO, ME?!"
"Shhhhhh!"
"Who, me?"
"Riiiiiiiiight."

Some Transformers toys come with multiple figures, such as a Pretender shell and its inner robot. Other toys are small and merge with bigger toys to become still larger. Other toys come with a trailer or base which has larger weapons than the core robot. Because of the size difference between the two components, two different weapon post sizes are required.

The early Pretenders usually handle this by simply giving the gun two different posts: a larger 5 mm post for the outer shell, and a smaller post for the inner robot. The result is that the two figures hold the same gun in different ways. For the purposes of this article, we'll refer to these as "multiple-post weapons".

Another solution, one often used with combiners, is simply to have the two posts one on top of the other—the smaller post on the bottom and the larger post on the top, both forming the same handle of the gun. Grimlock's accessories are one of the earliest examples (albeit unintentional), with rings or ridges widening the pegs to 5 mm. The problem with this solution is that, when one gives weapons to unrelated toys, Transformers with fist holes that don't go all the way through the hands (such as Armada Hot Shot) often can't hold these guns. We'll call that "double-posting" or "double-posted weapons" for the purposes of this article.

5 mm Screw Holes

Many Transformers over the years have indented holes to allow screws to hold two pieces of the toy together. These screw holes come in all shapes and sizes but often they are also 5 mm ports. Sometimes this is intentional, and the screw hole is deliberately moulded to 5 mm to give the toy more functionality. Most of the time though, they aren't intentionally 5 mm ports and are either very tight or slightly loose.

5 mm screw holes can add functionality to many toys which otherwise aren't 5 mm compatible, especially if a fan is creative. However, we have only included 5 mm screw holes in the compatibility list below if they are particularly notable. So if you suspect a toy's screw holes are 5 mm and it's not on the list, at least give it a try.

Powerlinx Pegs

I want it all, and I want it now!

During the Armada toy line, a new spin on the 5 mm post and port was developed: the Mini-Con Powerlinx. Using hollow 5 mm posts with a "trigger" contained inside, Mini-Cons could activate the gimmicks of other toys or simply mount on other toys. Because the Mini-Cons use a special kind of port, they cannot be mounted on 5 mm posts that aren't hollow. In theory, this means only toys with specific Powerlinx pegs can hold Mini-Cons. In practice, this isn't the case at all.

Throughout the history of the Transformers franchise, for one reason or another, toys have come with 5 mm posts which are hollow, creating a kind of unintentional back-compatibility with many Mini-Cons. We'll list this back-compatibility in individual toy entries further down the page.

The other significant aspect of the Powerlinx pegs is that they act like regular 5 mm posts too. This means that you can use them to mount any weapons or accessories that are designed to mount on 5 mm posts. Does mounting a bunch of miniature cars on Armada Starscream's arms seem silly to you? Maybe it's time to use the guns from the Micromaster Anti-Aircraft Base.

Generation 1

In the first few years of the toy line, partly because of the mix-and-match nature of the line itself, Transformers didn't have very standardised fist sizes. The Diaclone-descended toys usually had no single standard, with only the toys with the biggest weapons or fists having 5 mm posts. The Micro Change-descended toys were much more consistent about post size, using 5 mm posts on almost all of the toys with weapons or accessories, because of the size being one of the standard connectors for Microman toys.

As Generation 1 evolved 5 mm posts and ports became nearly universal. Only the switch to smaller toys with Action Masters changed this — a new, smaller, universal post size was used for that line. These smaller sized posts carried over into the UK Transformers, while in Japan the rise of Micromasters led to 5 mm staying predominant throughout the line.

1984

AUTOBOTS

• Optimus Prime — The only Autobot this year to use 5 mm posts, Prime's main rifle sadly has a terrible design flaw (that has never been corrected, despite all the reissues) which makes it much less interchangeable with other toys. The gun's handle is moulded in the wrong place, and there's a false handle where the real one should be. Prime has actually been retooled to allow him to hold the rifle better — by increasing the size of the rims on his fists. Too bad they didn't just put the rifle's handle post in the right place. In addition to the rifle, Roller's fuel pump is also a 5 mm post. It's possible to use this to either give the pump to other toys or to pump up Roller with some heavy weaponry.

DECEPTICONS

All the 1984 Decepticons use 5 mm posts in some capacity.

• Soundwave

Shattered Glass Ravage prefers flowers.

• Buzzsaw, Frenzy, Laserbeak, Rumble and Ravage — Due to the post holes in their bodies, they can be pegged onto Mini-Con ports, or similar 5 mm posts.

• Starscream, Thundercracker and Skywarp — Their wings and their weapons have 5 mm posts.

• Megatron — Most notably his large chrome rifle has a 5 mm post on it, allowing it to be given to other toys.

1985

AUTOBOTS

• Grimlock — Grimlock's fist holes are smaller than 5 mm (being the size of Rhisling's lower hilt), but ridges on the upper sections of his launcher and sword pegs and a ring on the upper part of the gun's peg make them 5 mm.
• Tracks — Tracks' missile mount is on a 5 mm peg. This means Tracks can have any 5 mm peg weapons mounted over his head or on his car or flight modes. Possibly the only Diaclone-based Autobot Car with a 5 mm weapon.
• Blaster
• Topspin and Twin Twist — These toys do NOT have 5 mm post holes, but their rifles have a 5 mm base to the gun peg, effectively creating a very shallow double-peg that allows their guns limited inter-changeability with toys with 5 mm fists.
• Perceptor

DECEPTICONS

• Devastator — Devastator's is a classic double-posted rifle. Devastator's fists are 5 mm holes, but he shares his rifle with Mixmaster and his tiny, tiny fists.
• Dirge, Ramjet and Thrust have the same 5 mm compatibility as Starscream and company from the previous year.
• Blitzwing — The strange construction of Blitzwing's weapons and fists makes interchangeability... awkward, as his fist holes are on the sides instead of the top; the weapons are sculpted to still look like he's holding them normally. Of course, if you're a fan of punch daggers, or Blitzwing holding someone else's guns 'gangsta-style', then more power to you.

1986

1986 saw the introduction of the Transformers Special Teams, or Scramble City-style combiners. All of these combiners used 5 mm posts as standard to peg in their fists and feet in combined mode, meaning you could swap these parts between any of the combiners. The fists of the combined forms almost universally used 5 mm holes (all except Superion and Piranacon) and almost all the leaders of the teams (except Silverbolt) used 5 mm posts for their fists.

The smaller members of the Special Teams almost all had small pistols or rifles that used variably compatible smaller posts, and larger alt mode weapons that used 5 mm posts — often taking advantage of post holes used for the combined form's fists or feet. The earlier toys often used weapons with 5 mm ports which would peg onto the robot — allowing those weapons to be pegged onto Mini-Con ports and other similar 5 mm posts. The later toys tended to use 5 mm posts which peg into ports on the toy.

AUTOBOTS

Where the bloody hell am I? Right here, mate. Right here!

• Outback — The only Mini Vehicle with a weapon at all, Outback sports a 5 mm post that lets him use all kinds of crazy weapons.
• Steeljaw and Ramhorn — But not Rewind or Eject, strangely. Ramhorn's peg holes are very loose.
• Superion — Barely. The Aerialbots are the only Special Team whose leader doesn't use 5 mm posts, and who have no members with larger vehicle weapons which use 5 mm posts. Superion doesn't have 5 mm fists either. Only the posts and ports for the combined form's hands and feet are 5 mm posts. Superion even has what looks like a hollow 5 mm peg on the underside of his combined form's chest plate — however this peg is just slightly too big to be of use.
• The Protectobots — In the standard style of the Scramble City teams, described above.
• Wreck-Gar
• Ultra Magnus — Most of Magnus' accessories use 5 mm posts. Interestingly enough his rifle has two ways of being held — the large robot uses a larger peg than the small inner robot's 5 mm post. So you can only let other toys hold the gun in the same way as Magnus' inner robot.
• Metroplex — Uses 5 mm posts for his weapons, and his fists. He can happily wear any Scramble City fists instead of his own. Six-Gun and Scamper do not use 5 mm pegs for their weapons, however Slammer does. His turret is on a hollow 5 mm post so it can be mounted on (or rather under, most of the time) Mini-Cons!

DECEPTICONS

• Ratbat
• The Stunticons — In the standard style of the Scramble City teams, described above.
• The Combaticons — In the standard style of the Scramble City teams, described above.
• The Predacons — Unlike the Scramble City toys, all the Predacons use 5 mm posts as standard, with no accessories at all with smaller pegs, making all their weapons usable by Predaking.
• Scourge — Only his head-mounted gun, his rifle uses a smaller peg.
• Galvatron — However remember, Galvatron's weapons pegs can be any size he wants!
• Trypticon — Full-Tilt does not use 5 mm posts. On the other hand, Brunt's tank turret does use them. It's completely possible to mount the turret as an arm cannon for an Armada toy, or anyone else with 5 mm posts.

1987

By 1987, 5 mm posts had become almost universal. Only some smaller toys, and those toys without weapon accessories, didn't have them.

AUTOBOTS

• The Technobots — In the standard style of the Scramble City teams, described in the 1986 section above.
• Fastlane & Cloudraker
• Punch-Counterpunch
• The Monsterbots
• The Targetmasters — Kup, Hot Rod and Blurr were retooled to be 5 mm peg compatible so that they could use Targetmasters this year. The other Targetmaster moulds were all made with 5 mm pegs in mind.

• The Headmasters — Fortress Maximus was the only Headmaster not to use 5 mm pegs exclusively. Nearly all his accessories and the weapons for his smaller components were 5 mm pegs. However his larger rifles were so huge they used much, much larger peg sizes which are not compatible with any other Transformers mould.

DECEPTICONS

• The Terrorcons — Blot and Cutthroat are the only small Special Teams members outside the Aerialbots not to have alt mode weapons with 5 mm posts. Blot has a backpack, and Cutthroat has a transforming tail weapon, instead.
• Slugfest & Overkill
• Pounce & Wingspan
• Sixshot
• The Targetmasters — Cyclonus and Scourge were retooled to be able to use the 5 mm pegs associated with Targetmasters and released again as part of this range.
• The Headmasters — Scorponok is the only Decepticon Headmaster not to use 5 mm pegs universally. Most of his accessories use them, except for his four large double-barrelled cannons and his shield, which has a slightly wider peg hole. The shield does have a hollow 5 mm peg on it, though, allowing you to mount a Mini-Con on the shield. Sweet! Oh yeah, that does mean, by the way, that his tremendously enormous rifle does use both 5 mm pegs and 5 mm peg holes. Fasttrack doesn't use 5 mm pegs for his hands, but his arms are mounted on 5 mm pegs, so you can give him all sorts of crazy gun arms.

1988

5 mm pegs on Pretenders: A demonstration.

1988 introduced a new line dependent on the 5 mm peg, the Pretenders. As mentioned above, in the section on multiple posts and double posts, the Pretender shells all had 5 mm pegs, while their robots had smaller (less universally sized) pegs. Pretenders usually had at least one weapon (sometimes more) that was meant for both the shell and the inner robot. For the 1988 Pretenders, these weapons had multiple pegs on them, allowing different components to hold them in different ways. These weapons were also usually a part of the Pretender's vehicle mode, and mounted on them in that mode using 5 mm pegs.

Later Pretenders used double-posting instead of multiple-posting, so that the inner robots often lacked the 5 mm compatibility in their vehicle modes that earlier Pretenders enjoyed. But for 1988 it was 5 mm compatible city!

AUTOBOTS

• Grand Slam & Raindance
• The Targetmasters
• The Headmasters — Unlike in 1987, the 1988 Autobot Headmasters had two sets of weapons with different post sizes. There was a single main rifle for the main robot with a 5 mm post, and two smaller pistols that were both vehicle mode weapons and antennae for the robots' head.
• The Powermasters. — Powermaster Prime in particular is notable because his weapons are massive, badass and freakin' awesome. You know they are. Admit it.
• Quickswitch
• The Pretenders — Including the regular Pretenders, Pretender Beasts and Gunrunner, the Pretender Vehicle.

DECEPTICONS

That gun mode stinks!

• The Seacons — Because of his Targetmaster gimmick, Piranacon is one of only two (the other being Superion, the piker) Generation 1 combiner robot without 5 mm post hole fists. Instead he has special ports for the square pegs which are used as part of the Special Teams style combination. Each of the five smaller Seacons also come with a special Targetmaster stand which allows them to use their gun forms independent of Piranacon. The stand is divided into three parts, a connector, a post and a base. The post is moulded to look like a large rifle and has multiple pegs on it (of different sizes) letting it be held as a weapon both by the small Seacons and by anyone with a 5 mm fist. The connector is even cooler, since it has a 5 mm post hole and can be used to mount the Seacons on Mini-Con ports or other similar gun posts when in gun mode. It can also be used to make any Scramble City style combiner limb 5 mm post compatible, so any of them can become a giant Mini-Con. How awesome is that?
• Squawktalk & Beastbox
• The Targetmasters
• The Headmasters — The small Decepticon Headmasters did not have two sets of weapons like their Autobot counterparts and relied entirely on 5 mm posts.
• The Powermasters — Doubledealer came with a special Powermaster Engine cover with a 5 mm post on it. The post is hollow, allowing you to mount a Mini-Con on it.
• The Pretenders — Including the regular Pretenders, Pretender Beasts and Roadgrabber, the Pretender Vehicle.

1989

This year introduced the Micromasters together with a truckload more Pretenders. The Micromasters emphasized inter-compatibility in a way Transformers hadn't really done before. All the bases were able to connect through special ramps, and all the weapons for the bases used 5 mm posts. The Micromasters themselves all had small ports in their feet that corresponded to small posts all over the bases — letting you stand them freely. The Micromasters' association with 5 mm pegs would continue through into the Japanese toy lines, and would be reflected in the Mini-Cons who would come down the pipeline many years later.

As mentioned above, the Pretenders this year were a little less 5 mm compatible. While the first-year Pretenders generally had 5 mm ports on their vehicle modes as well as their Pretender shells, those ports disappeared on most of the inner robots for this year. Instead of using multiple posts on the same weapon, more toys this year used a double-post.

AUTOBOTS

Literally all the Autobot Pretenders from this year used 5 mm posts. All of the Micromaster bases and transports except for Overload and Hot House used 5 mm posts for their weapon accessories. Hot House and Overload don't really have any accessories, so that's understandable.

• Pincher, Doubleheader and Longtooth
• Classic Pretenders — Bumblebee, Grimlock and Jazz. These toys were re-released without their shells as Legends. They only came with their smaller weapons, which are double-posted. While the inner robots can't hold 5 mm weapons their weapons can be used with other toys. Bumblebee and Jazz's guns were switched for the Legends release, so if you're pedantic about continuity feel free to give Jazz's gun to Classics Bumblebee without feeling guilty.
• Crossblades and Vroom
• Skyhammer

• Erector and his Crane — Erector's weapons are all 5 mm posts. While Erector's trailer hitch is not a 5 mm post it is hollow and works as a 5 mm port, allowing Erector to connect to other TFs and bases like a Mini-Con.
• Ironworks' Construction station — In station mode, Ironworks's base has two hollow 5 mm posts on its scaffolding section. These are completely compatible with Mini-Cons. In windmill... errr... radar tower mode these two pegs are used to mount the scaffolding to the tower, so aren't accessible.
• Groundshaker's ATV and Countdown's Rocket base

DECEPTICONS

All the Decepticon Micromaster bases and transports were 5 mm compatible this year in some capacity. The Pretenders also, except for the Monster Pretenders.

• Monstructor — As with nearly all combiners, Monstructor uses 5 mm fist holes. However none of the individual Monster Pretenders do. Their shell covers sometimes have relatively inaccessible 5 mm posts or ports for Monstructor's accessories, but that is more-or-less the extent of their compatibility.
• Octopunch, Stranglehold and Bludgeon
• Classic Pretenders Starscream — Also available as a Legends figure without any of the 5 mm compatibility conferred by his shell.
• Thunderwing
• Roadblock

• Flattop's Aircraft carrier and Roughstuff and his Military transport — Roughstuff's missiles and turret are the only large Micromaster weapons without 5 mm posts, making him far less compatible with other toys than he should be. However his trailer hitch is a 5 mm post and port. That might be of... some use.
• Greasepit's Gas station and Airwave's Airport — Greasepit has a host of little 5 mm post accessories that aren't weapons like a set of petrol pumps and a street sign. Airwave's compatibility is limited to having several 5 mm ports on the top of his base's station mode.
• Skyhopper's Helicopter and Skystalker's Interstellar shuttle

1990

Action Masters dropped the 5 mm posts in favour of a smaller standard-sized peg for hand-held weapons, obviously due to the smaller size of the figures' fists (these holes are the right size for vintage G.I. Joe weapons and accessories). However, the backpack accessories for the individually carded figures use 5 mm pegs to attach to the screw-holes in the figures' backs, making them compatible with weapons for larger toys. Some of the bases use 5 mm posts for their weapon systems as well. But for the most part, this was the end of 5 mm pegs being universal in Transformers for a very long time; it wouldn't happen again until the Unicron Trilogy, almost a decade later.

AUTOBOTS

Another example of why beards freakin' rock.

• Lionizer — Because of his beard, he actually has a double-post, so he has a 5 mm post, though it's very tight.

• Prowl's Turbo Cycle. — The cycle's engine intakes have a 5 mm port, so they can be mounted on Mini-Con pegs if you'd like. The wheel section uses a 5 mm post to connect to the cycle, as does the hinged side-cover section, which could also be posted on Prowl's back to approximate his original toy's door "wings". The rest of his accessories use the more standard smaller pegs used by Action Masters.
• Over-Run. — While both he and his helicopter aren't really 5 mm compatible, he does have hand-held missile launchers with 5 mm post holes on them. They can be mounted on Mini-Con ports, or you can mount 5 mm guns on top of them while Over-Run is holding them — but good luck keeping his arms up. There's a couple of posts on the back of his helicopter as well.
• Optimus Prime's Armored Convoy — Has a bunch of black guns and orange guns with 5 mm posts. Yes, you can give all these weapons to Classics Primes. The black guns have hollow posts and so can be mounted on Mini-Cons. The entire Armored Convoy, both cab and trailer, is littered with 5 mm ports.

• Missile Launcher (with Retro & Surge) and Tanker Truck (with Pipeline & Gusher) — Both bases have a new mould Micromaster ramp with a double-peg on it. Unfortunately it's very hard to access, and not very effective as a shield for other toys. The combiner bases also extensively use 5 mm ports and pegs for all their weapons, and even their main combining pegs. This means they can be connected to each other, or to any other 5 mm pegs or ports.
• Battlefield Headquarters with Full-Barrel & Overflow

DECEPTICONS

• Megatron's Neutro-Fusion Tank
• Gutcruncher's Stratotronic Jet — His missiles have 5 mm post holes, rather than 5 mm posts. This means you can mount his missiles on mini-con ports or other similar 5 mm posts.

Blackout and shout!

• Cannon Transport with Terror-Tread & Cement-Head — Features the same 5 mm compatibility as the Autobot Combiner Transports.
• Anti-Aircraft Base with Blackout & Spaceshot — Is one of the most versatile 5 mm-compatible toys of all time. All up the base features eight 5 mm ports, seven 5 mm posts and a variety of different accessories. The base's main guns are designed to peg onto 5 mm posts so can be used with mini-con ports. The base's radar equipment and additional weapons are all designed with 5 mm posts. Even the base's ramp features a 5 mm port, rather than the limited 5 mm post of the Micromaster Combiner Transports. The four 5 mm posts on the base proper are hollow, also allowing them to be used as mini-con ports.

UK Generation 1

After Generation 1 ended in the US it continued in the UK unabated. Well, a little bit abated. It wasn't as big as it was. The UK line at first consisted of redecos of Japanese toys and Action Masters that hadn't made it to America. After that they continued to produce their own toys. Okay... but what does that have to do with 5 mm pegs? Well, sadly, not much. The UK lines did not make extensive use of 5 mm pegs, even when they really should have (we're looking at you, Predator jets). The compatibility of these toys is incredibly limited.

1991

The Action Masters from this year didn't use 5 mm pegs at all, meaning that there were only three toys this year with 5 mm pegs.

AUTOBOTS

Ready for a Flame war!

• Flame, Gripper, Lightspeed. — The Motorvators, being recycled Japanese toys, used 5 mm pegs as standard for their weapons. Their weapons had two sets of pegs letting them be held as swords or guns.

1992

This year introduced the Turbomasters and Predators. Even though both sets of toys (who all have massive guns) would have benefitted from 5 mm posts, only two toys out of the entire line have them.

AUTOBOTS

• Rotorstorm

Stalk 'er? I hardly knew 'er.

DECEPTICONS

• Stalker — Unlike Rotorstorm, his hands are not 5 mm peg holes. Instead, the ports on his shoulders and back are 5 mm pegs — his massive missile and his radar dish are on 5 mm posts. His lack of 5 mm hands is made up for by two screw holes on his wrists which are 5 mm holes, allowing him to hold guns there.

1993

AUTOBOTS

• Pyro

DECEPTICONS

• Clench

Japanese Generation 1

There's not a lot to say about Japanese Generation 1. The main thing is that there are more Micromasters. More Micromasters means more 5 mm pegs.

The first few lines that the Japanese marketed independently were mostly reuses of American moulds, with only a few differences. Basically, if the American version can use 5 mm pegs, so can the Japanese version. In these cases, there's only a handful of toys that need pointing out as independent and unique but the overall line was generally a mess of 5 mm pegs everywhere.

Headmasters

Most of this line was just American release toys repackaged. Basically all of them were 5 mm compatible. Almost all of the moulds unique to the Japanese line were also 5 mm compatible.

CYBERTRONS

• Stepper and Artfire. — Jazz and Inferno, two previously non-compatible toys, were retooled and redecoed in Headmasters and used as Targetmasters. Artfire's fists are expanded to allow him to hold his targetmaster gun Nightstick. Stepper meanwhile has Jazz's missile launcher replaced by a plug-in port to allow him to use his Targetmaster unit Nebulon as a shoulder cannon.
• Billy Blaster Twincast — Redeco and slight retool of G1 Blaster.

• Graphy, Noise, Dile and Zaur
• Raiden — Like Devastator before him (well, sorta), Raiden can use 5 mm weapons while his components cannot.

DESTRONS

• Soundblaster — Redeco and slight retool of G1 Soundwave.

Masterforce

Again, Masterforce is almost entirely American moulds, but this time there's more redecos. There's a few retools, and a handful of new moulds too, with 5 mm compatibility.

CYBERTRONS

• Metalhawk — He's a Pretender. And what have we learned so far? That's right: Pretenders are 5 mm compatible.
• Super Ginrai and Godbomber — Ginrai is a retool of Powermaster Optimus Prime, with brand new hands. Brand new retractable 5 mm hands! (To replace his old unretractable 5 mm hands!) Godbomber is designed to be compatible with Ginrai, to use his accessories and to merge with him, so he gets to be 5 mm compatible too. Sweet.
• Grand Maximus — Fortress Maximus with a new deco and some new accessories. He's compatible with 5 mm pegs in the same way as Fortress Maximus, and his new parts are mostly a Pretender shell with some extra weapons. Pretender shell? Well, we know what that means!

DESTRONS

• Overlord — Does not have 5 mm peg holes for his hands, but has limited compatibility thanks to a handful of 5 mm holes and some 5 mm pegs on his smaller accessories. This toy was also released in Europe in 1992.
• Browning — As well as multiple sets of fists, Browning also has 5 mm post holes on his shoulders for added shoulder cannon action.
• BlackZarak — A retool of G1 Scorponok with a new robot mode head and some new weapons. He's 5 mm compatible in the same ways as Scorponok, but with updated Gold Plastic Syndrome compatibility to boot.

Victory

Victory was radically different from the American toy line of the time. Most of the toys were unique to Japan, and most of them had 5 mm compatibility to some extent.

CYBERTRONS

• Star Saber, Victory Leo and their combined form Victory Saber
• Blacker, Laster, Braver and their combined form Road Caesar.
• Landcross — While the individual components are not generally 5 mm compatible, Landcross has 5 mm fists. Some of his components have 5 mm holes on their vehicle modes for storing merge parts.
• Galaxy Shuttle — Dude's basically a Micromaster toy, of course he's 5 mm compatible.
• Greatshot — A retool and redeco of Sixshot.

DESTRONS

• Liokaiser — As with most every merge group, Liokaiser's fists are 5 mm pegs. His individual components are mostly not 5 mm compatible. Leozack has 5 mm ports, and Guyhawk and Hellbat have 5 mm posts, used in merging. Killbison's tank mode guns are on a 5 mm plug, which becomes Liokaiser's hand-held weapons. None of these ports and plugs are particularly accessible or useful. Unless you want to give Leozack gun knees, which... who wouldn't want to?
• Dinoking — A redeco of Monstructor with new Pretender shells, he's 5 mm compatible in exactly the same way.
• Black Shadow and Blue Bacchus — Retools and redecos of Crossblades and Thunderwing.

Zone

Zone is basically the Japanese equivalent of the American Micromasters line. Most of the toys were straight repackagings of the American releases, with basically no changes. The rest were either new Micromaster bases (with 5 mm weapons) or redecos of American bases. 5 mm compatibility had been more or less the norm for Japanese Generation 1, and Zone would cement their place with only the individual Micromasters not being fully 5 mm compatible.

CYBERTRONS

• Dai Atlas, Sonic Bomber, Road Fire and their merged form Big Powered
• Landshaker and Sky Hyper — Redecos of Groundshaker and Sky Hopper's bases with new pilots and the same ole weapons.

DESTRONS

• Metrotitan — Dude, a crazy Decepticon redeco of Metroplex. Just as compatible with 5 mm pegs as Metroplex ever was. But more blue.

Return of Convoy

Is there nothing they can't do?!

Yup, Optimus Prime got a new toy this year. Yawn. What we're really interested in is two brand new concepts. First of all, all the Micromaster patrols were re-released this year, and packaged with brand new Micro Trailers. Secondly we were introduced to six-member Micromaster combiner teams which merge more traditionally than the American Micromaster combiners.

The Micro Trailers were simple launchers for the Micromasters, and there were (including the three packaged with the bulks from this year) 14 in all. From a 5 mm compatibility point of view, these things are incredible. They're designed to combine, pegging into each other. The result is two hollow 5 mm posts, and two 5 mm ports on each little trailer. You can load them up with weapons, plug Mini-Cons into them or just have larger robots hold them as weapons. Just to add to it, they've got ports for American Micromaster Combiners to tow them with, connectors for Micromaster ramps, and a tab to let Sky Garry carry them. Interactivity? You freakin' bet.

The six member combiners are significant because they are the first (and only, until the release of Legacy Volcanicus some 32 years later) combiner teams to use 5 mm pegs to connect actual robots together. The six Micromasters in each team combine around a frame that makes up the torso, head, and thighs of the robot. The shoulders of this frame use hollow 5 mm pegs to connect its arms. It's significant because it means that the arm components for all the six member Micromaster combiners have large 5 mm ports, allowing them to peg onto 5 mm posts — like Mini-Con pegs, for example.

CYBERTRONS

• Grandus, Sky Garry, and Star Convoy
• Micro Trailers #0 to 12, and Star Convoy's Micro Trailer.

• Sixliner — Sixliner was the first of the six member Micromaster combiner teams. He had 5 mm compatible fists, a 5 mm compatible gun (with two hollow 5 mm pegs on the side) and oddly enough 5 mm compatible toes. His combiner parts can all become carriages for the train modes of his individual Micromasters. His main torso section has three hollow 5 mm posts on it, allowing it to mount Mini-Cons, or to be held by larger robots as a strange gun (which you can then mount Mini-Cons on). Sixliner's arms, Leaf and Alan connect to him via 5 mm ports that can be used to peg them on any 5 mm posts.

Operation Combination

The last gasp of Generation 1 in Japan. This line was a mish-mash of new moulds, redecos of old moulds and UK imports.

The most important part of the line from our point of view right now is the new six member Micromaster combiners. There was a retool of Sixliner, and 3 entirely new mould teams. The three new teams use a generic body frame which uses far more 5 mm pegs than the Sixliner body. The head and feet, as well as the shoulders, now connect by 5 mm posts. This new versatility meant that four members of the team, not just two, could peg onto 5 mm posts. The parts of these new combiners could also merge into a jet — but if you merge them into a jet you can't use the parts as weapons for larger robots, and who wants that? No one.

CYBERTRONS

• Sixturbo — His arms and legs, Circuit, Neo-Wheel, Discharge and Sireen all have 5 mm ports.
• Sixbuilder — His arms and legs, Digger, Iron Lift, Mixing and Treader all have 5 mm ports.
• Sixwing — His arms and legs, Falcon, Flanker, Raker and Supersonic all have 5 mm ports.
• Guard City — A redeco, barely, of Generation 1 Defensor. Compatible in exactly the same way as the original mould.
• Sixtrain — A retool of Sixliner. His arms Atlan and Raise have 5 mm ports.

DESTRONS

• Battle Gaia — A redeco of Generation 1 Bruticus. Compatible in exactly the same way as the original mould.

Generation 2

Come 1993 and Transformers was given a rebirth, both in the US (who hadn't had toys on the shelves since 1990) and in the rest of the world, called Generation 2. This toyline was a mixture of vintage Generation 1 Diaclone-based toys, redecos of toys released in the UK and later on a whole slew of brand new moulds created just for that line.

Generation 2 was only moderately 5 mm-friendly. The old moulds retained their old compatibilities, and the new moulds tended to be much smaller toys that weren't able to have large fist holes. Still, there are a handful of new and interesting toys with 5 mm compatibility, and many of them would go on to be prominent toys in later lines as well.

1993

AUTOBOTS

• Optimus Prime — This toy is a redeco and retool of Generation 1 Optimus Prime. The main difference now is the addition of a voice pack with two 5 mm post holes on it and the addition of two brand-new hand-held missile launchers with 5 mm posts. This added versatility has basically never been carried forwards to other re-releases of the mould.
• Jazz and Sideswipe — These two (redecos of the G1 toys) are NOT 5 mm compatible, but their missile launchers have a double-post, making their guns 5 mm compatible.

DECEPTICONS

• Devastator — This toy was released twice in two different new decos, but it's still the same tooling as the Generation 1 toy with the same compatibilities.
• Ramjet and Starscream — Redecos of the Generation 1 toys with the same compatibilities. They also have new missile launchers (that actually launch!) and a new sound box, but neither of these really adds any new compatibility to the toys.
• Megatron — This is the first new Gen2 exclusive mould created for the American toy line. It's also the first new mould with 5 mm fists.

1994

AUTOBOTS

• Superion — A redeco of the Generation 1 toy, with the same very very limited compatibility, but with the added bonus of Gold Plastic Syndrome.
• Silverbolt — A redeco of the Generation 1 toy, unlike the original toy this Silverbolt is retooled to have 5 mm post holes on his wings, for a pair of new missile launchers. Silverbolt's launchers are the same basic mould as those used by the Skyraiders, but were retooled to have a double-post so that Superion could hold them. Because he doesn't have 5 mm fists. Because Superion is a poopy-head.
• Hero Optimus Prime
• Electro and Volt.

DECEPTICONS

• Bruticus and the Combaticons — A slightly retooled and extensively redecoed version of the original toy with the same basic compatibilities. Onslaught also has a new missile launcher which is 5 mm compatible.
• Hero Megatron
• Sizzle and Jolt

1995

The last year of Generation 2 was getting more and more experimental, with toys with all kinds of different gimmicks, all kinds of brand new features. Unfortunately this year also saw a severe downsizing of the toys — smaller toys became the standard. That left room for only one toy this year with 5 mm fists and accessories.

AUTOBOTS

• Laser Optimus Prime — Probably because of a decided downturn in the size of individual toys in 1995, Laser Optimus Prime is the only toy this year with 5 mm pegs. His sword, laser cannon, and missile launcher have 5 mm handles.

Beast Wars

Share and share alike.

After Generation 2, 5 mm posts took a pasting. Suddenly they just weren't standard any more. If Generation 2 was experimental in its last days, then Beast Wars was even more experimental. There were basically no singular standards for this line. Characters were completely self-contained play patterns, based around their animal modes. As the line evolved general gimmicks, again based on the aesthetics of the toy rather than their play pattern, began to dominate. The only place that 5 mm post holes were generally universal were the larger scale Ultra toys who mostly featured 5 mm hands.

Tolerances are a big issue with Beast Wars toys with 5 mm posts, the following list is as comprehensive as it can be, but you might find you struggle to use the 5 mm compatibility on some of your toys. In the testing phase different samples ranged from impossibly tight, to perfect, to really loose.

1996

MAXIMALS

• Dinobot — Dinobot's weapons and accessories and hands are all 5 mm posts. This is great, seeing as this mould was released again, and again, and again. His famous rotating blade weapon has a 5 mm post hole in it that allows it to mount on a 5 mm post on his dinosaur mode back. This is especially useful for mounting the tail weapon on his back in robot mode.
• Polar Claw
• Ultra Optimus Primal
• Wolfang — Has 5 mm screw holes in his robot back, and a non-screw 5 mm hole in his head — these are almost useless. However, his waist kibble has Mini-Con-compatible pegs, as does the front of his shield.

1997

MAXIMALS

• Grimlock — A redeco of the Beast Wars Dinobot mould with the same compatibility.
• Ironhide and Magnaboss — Silverbolt and Prowl are not 5 mm compatible, but Ironhide, Magnaboss' sword, and Magnaboss are. The small hollow pegs on Ironhide's elephant shell halves are not 5 mm, but the size of the inner hole is such that they do grip Mini-Cons.
• B'Boom

PREDACONS

• Ram Horn and Tripredacus — Ramhorn has 5 mm hands, giving Tripredacus one 5 mm hand too. The other members of the team are not 5 mm compatible.
• Inferno

1998

MAXIMALS

• Transmetal Cheetor — His fists are an unconventional shape, but hold 5 mm weapons just fine.
• Transmetal Optimus Primal
• Optimal Optimus — While he doesn't have 5 mm peg holes for his fists, he does have 5 mm pegs on his wrists, (on angles, so their use is limited) and he does have hollow 5 mm pegs (perfect for Mini-Cons) on his rifle! On his shoulders are a couple of other 5 mm pegs too.

• Torca

PREDACONS

• Transmetal Megatron
• Transmetal Rampage
• Botcon Antagony

1999

MAXIMALS

• Optimus Minor — On his own, Optimus Minor is not 5 mm compatible. However, his tail weapon uses two different 5 mm pegs — one of which is hollow, perfect for Mini-Cons! The allows him to hold a Mini-Con in robot mode.
• Tigerhawk

PREDACONS

• Transmetal II Megatron

Beast Wars II

Beast Wars II was a Japanese only line capitalizing on the success of Beast Wars. It's mostly a redeco line, with a handful of brand new toys or moulds. There's a bunch of old toys in this line with 5 mm compatibility, and a few retools and redecos. There's only one new mould. Lio Convoy looks like he should have them, but his fists are actually a bit bigger than the 5 mm standard.

Autolauncher, a canceled Generation 2 toy.

CYBERTRONS

• Lio Convoy
• Santon and Magnaboss — Redecos of Beast Wars Ironhide and Magnaboss.

DESTRONS

• Autolauncher
• Megastorm
• Gigastorm
• Thrustor
• God Neptune — A redeco of the Seacons minus Nautilator, with most of the same 5 mm compatibilities as the original group. They were released in a gift set, and also lacked the individual gun stands that the original Seacons had. Man... sucky.
• Galvatron

Beast Wars Neo

That peg placement could be worse...

CYBERTRONS

• Big Convoy — Includes a 5 mm peg-compatible Matrix.
• Longrack
• Break — 5 mm peg under each wing to use him as a missile launcher
• Stampy — 5 mm peg on his chest (with embossed Maximal symbol on the end) so his blade weapon mode can be held

DESTRONS

• Hardhead
• Elphaorpha

Machine Wars

"They may take my weapons, but they'll never take my 5 mm holes!"

Machine Wars also had a lack of support for the 5 mm peg, although this stems from the line re-using old European exclusive molds, or unused molds from Generation 2. However, the two releases in the Megas size did make use of 5 mm posts. As they were once Rotorstorm and Stalker respectively, their use of 5 mm ports are identical to their original releases.

1997

AUTOBOTS

• Sandstorm

DECEPTICONS

• Soundwave

Beast Machines

Beast Machines saw the almost complete abandonment of the 5 mm peg for its toys. The introduction of uniquely moulded hands and toys with few if any accessories meant that 5 mm peg holes were no longer needed. In fact, in all of Beast Machines, there is only one toy with deliberate 5 mm peg holes for hands. There's others with 5 mm screw holes or 5 mm peg holes that can be used to make them compatible with older weapons, but for the most part, Beast Machines emphasized completely self-contained toys.

On the flip side, Beast Machines was one of the first Transformers lines to introduce vehicles and separately sold weapon-accessories for other toys, in the form of the Beast Riders and Deployer assortments. These toys, while emphasizing interactivity with other toys, did so without the use of pegs.

2000

VEHICONS

• Megatron — The only toy in the entire line that's deliberately 5 mm compatible, the Mega-sized Megatron toy has a single 5 mm fist in robot mode.

2001 Robots in Disguise

Unlike the much more focused and consistently designed Beast Machines, 2001 Robots in Disguise was an absolute hodge-podge of a line. It used a combination of new moulds, vintage moulds, and contemporary redecos that saw toys from all over the place incorporated into the line. This was both good and bad for 5 mm peg enthusiasts—mostly bad, since the majority of the redecos came from Generation 2 Go-Bots or Beast Wars and Beast Machines toys.

The handful of brand new toys in the line didn't really emphasize interactivity through compatibility of accessories. Instead they emphasized interactivity through figure combination. Still, there's a handful of stuff there worthy of inclusion here.

2001

AUTOBOTS

• Wedge, Heavy Load, Hightower, Grimlock and Landfill — Grimlock is the only member of the team lacking 5 mm fists, but fortunately he makes up for it in combined form where he forms a part with 5 mm compatible hands (well, claws) for Landfill. In fact all of Landfill's configurations are 5 mm compatible. Woo!

• Optimus Prime and Ultra Magnus — Both use 5 mm posts extensively. Only the smaller, non-super mode Prime actually has 5 mm FISTS. Prime's super mode lacks 5 mm fists, or fists at all. Omega Prime's and Ultra Magnus's hands do have 5 mm holes on the palms, and Magnus's thumbs have 5 mm posts. Prime is also covered in a bunch of hollow 5 mm posts that can be used as mini-con ports, and both have 5 mm posts and holes out the wazoo.

DECEPTICONS/PREDACONS

• Ruination — Ruination is a redeco and slight retool of the Generation 1 Combaticons. Initially, in Robots in Disguise, all five components were released separately, though later on they were released only as gift sets. The main difference to the moulds is that the Combaticons' weapons were retooled so they could create two super weapons for Ruination. These super weapons are 5 mm compatible.
• Megatron and Galvatron

2002

DECEPTICONS/PREDACONS

• Cryotek — A redeco of Beast Wars Transmetal 2 Megatron, has 5 mm fists just the same.
• Scourge — A redeco of Generation 2 Laser Optimus Prime with all his compatibilities.

2003

AUTOBOTS

• Landfill — Same compatibilities as ever, but now in yellow! Plus, it's a gift set!

DECEPTICONS

• Destructicon Scourge — A redeco of Generation 2 Hero Optimus Prime.
• Destructicon Bludgeon — A redeco of Generation 2 Hero Megatron.
• Ruination — Same as before, but now more urban! And in a gift set!

Armada

For 5 mm peg addicts, the Unicron Trilogy was a godsend. It was the first Transformers toyline not only to feature 5 mm pegs as standard on nearly every single toy, but also to advertise this interactivity. It's all down to one thing: Mini-Cons. Mini-Cons and their contribution are covered a bit earlier in this article, but it's important here to mention their... well...importance.

Mini-Cons each came with a 5 mm peg hole, with a smaller (1mm?) peg imbedded inside it. Mini-Cons could then plug onto hollow (but NOT solid) 5 mm pegs, usually referred to as Mini-Con hardpoints. Some of these hardpoints included small triggers which were pushed down by the smaller peg inside the Mini-Con's 5 mm post hole. This activated gimmicks on the larger toys, and is why the Mini-Con don't simply have 5 mm post holes.

The inclusion of Mini-Cons as a set of figures compatible with all larger Armada figures saw an overnight change. Suddenly 5 mm pegs were the standard again and all but the roleplay toys in the Armada line have 5 mm pegs. However, carrying on from Beast Machines and Beast Wars, many Armada toys had unique or oddly moulded hands, which is madness when you have add on weapons with 5 mm pegs and lots of the toys can't hold them. 5 mm fists would not make their complete comeback until Energon.

2003

MINI-CONS

The Mini-Cons are all 5 mm-compatible in the same way: All Mini-Cons can peg onto any hollow 5 mm pegs. Specific toys that can use them which aren't part of the Unicron trilogy are discussed all through this article, including RiD Optimus Prime, the Micromaster Anti-Aircraft Base, and Beast Wars K-9. Listed below are specific Mini-Cons with unique 5 mm compatibilities not covered by straightforward Powerlinking.

• Over-Run and Run-Over — Transform into guns with 5 mm-compatible handles.
• Rollout — He has a 5 mm-compatible trailer hitch that can be used as a Mini-Con port, allowing other Mini-Cons to peg onto him!
• Leader-1 and Clench — Both have 5 mm-thick arms, allowing them to become 5 mm-compatible guns.
• Sonar and the Star Saber — The Air Defence Team merges to become the Star Saber sword. The sword can be held by any toys with 5 mm fists or pegged onto Mini-Con compatible posts. Of the three members of the team, only Sonar has an extra feature. He has a 5 mm post accessible mostly in shuttle mode, allowing him to be held in other figures' hands (as well as allowing him to be the base of the Star Saber sword).
• Maverick and the Dark Saber
• Prowl — Prowl transforms into a 5 mm-compatible gun.
• Dirt Boss and the Skyboom Shield — The Race Mini-Con Team merge into an enormous shield designed for use with larger toys with 5 mm-compatible fists. Dirt Boss has a 5 mm-compatible head because of this. Yeah, you heard right, his head is a 5 mm post.
• Payload, Sky Blast and the Requiem Blaster — The Space Team merge into the Requiem Blaster, a super-gun meant for use by toys with 5 mm-compatible fists. Payload has the 5 mm peg that becomes the handle for the blaster, so he can be hand-held. Sky Blast also has a 5 mm peg, this one hollow so that you can mount other Mini-cons on top of the Requiem Blaster and power it up even MORE. Yeah. Insane, right? It also means Sky Blast can be hand-held or merge with Energon weapons, etc.
• Grindor — In skateboard mode, he has a Mini-Con compatible peg on top of him, allowing other Mini-cons to be plugged into him.

AUTOBOTS

• Blurr, Smokescreen and Hoist — None of these three moulds sport 5 mm hands. Smokescreen has a 5 mm screw hole on his arms just below his fists which can be used as a kind of 5 mm fist, but neither Blurr nor Hoist have 5 mm fists at all. Smokescreen even came in a boxset with the Skyboom Shield in Japan and he can't hold it!
• Hot Shot, Powerlinx Hot Shot, and Side Swipe — All feature standard 5 mm fists. Side Swipe even has a 5 mm-compatible gun. In Japan, Hot Shot was given an LED in one hand to allow him to light up 5 mm-compatible translucent weapons.
• Airazor, Cheetor, and Rhinox — Three redecos of Beast Wars toys, they were retooled so they would have Mini-Con hardpoints. They were not retooled to have 5 mm compatible fists, however, so neither Rhinox nor Airazor can use 5 mm-compatible weapons. Cheetor still can, though.
• Red Alert and Powerlinx Red Alert — Red Alert is 5 mm compatible out the wazoo. He has Mini-Con pegs all over, plus a 5 mm fist, a 5 mm port on his shoulder for shoulder cannons, a 5 mm compatible rifle... oh yeah, and interchangeable tool hands which plug in using a 5 mm peg.
• Scavenger — He doesn't have 5 mm-compatible hands. But he does have big, stompy feet, so we forgive him.
• Overload, Jetfire and Powerlinx Jetfire — Both moulds have 5 mm fists, though Overload's are very limited due to his enormously high wrists. Overload also has a 5 mm-compatible port as his trailer hitch so he can be towed by Optimus Prime or his Mini-Con.
• Supercon Optimus Prime, Super Optimus Prime and Powerlinx Optimus Prime — Both the large and small Optimus Prime toys have 5 mm fists. Even in his Super Mode, Prime has 5 mm fists. The hitch used to pull Prime's trailer is a 5 mm post, shared by both the large and small versions of the toys. This means that the small Prime can pull the larger toy's trailer, or either of them can pull Armada Overload. You can also use this hitch as a mount for 5 mm compatible weapons.

DECEPTICONS

• Cyclonus, Powerlinx Cyclonus, Demolishor, Powerlinx Demolishor, Thrust and Powerlinx Thrust — Do not have 5 mm compatible fists. They do have plenty of Mini-Con ports, though.
• Wheeljack — The only Supercon Decepticon with 5 mm-compatible fists. He also has missiles that he uses as clubs (well, in the fiction he uses them as guns...sorta...), and they're 5 mm compatible too.
• Nemesis Prime — A redeco of Supercon Optimus Prime. He has all the same compatibilities, including being able to pull the Super Prime's trailer.
• Terrorsaur — A redeco and retool of Beast Wars Transmetal Terrorsaur. The retooling gives him Mini-Con pegs, but not 5 mm-compatible fists.
• Predacon — A redeco and retool of Beast Wars TM Megatron. Like the original version of the mould, he has 5 mm fists and a 5 mm tail weapon, but now he also sports four brand new Mini-Con pegs.
• Starscream, Skywarp and Thundercracker — All have 5 mm hands in addition to their Mini-Con pegs.
• Tidal Wave — Doesn't have 5 mm fists, even if he is loaded with an unbelievable number of Mini-Con ports.
• Megatron and Galvatron — They traded useless knees for unreasonable numbers of Mini-Con hardpoints. Their insane number of Mini-Con pegs makes them one of the most 5 mm compatible moulds in history. The toy is perfect for overloading with weapons in either robot or tank mode, and in robot mode, he even gets a 5 mm-compatible fist (only the one, because the other hand is concealing a knife).
• Unicron - In total, the planet-eater has 27 Mini-Con-compatible pegs in planet mode and 30 in robot mode — 32 if you count the two conveniently shaped pegs on the back of his right hand. Of those, 24 are situated on his wings/planet ring.

Energon

Now his shot's 6 times as hot!

With Transformers Energon, the 5 mm golden age continued. Mini-Cons were dropped in favour of a return to the basic price point, but Energon figures still retained their 5 mm compatibility and their Mini-Con hardpoints. The line introduced new translucent weapons called energon weapons. The energon weapons were versatile, often multi-part weapons which frequently had both traditional 5 mm posts and ports and Mini-Con-style 5 mm posts and ports. They could be mounted on Mini-Con pegs, used to activate Mini-Con gimmicks on Armada toys, and merged to create insanely over-the-top super weapons.

There were two distinct types of energon weapons. There were the multi-part accessories packed with the Omnicons, which often had 3 or 4 distinct components. Strictly speaking these (and a few weapons of larger toys) were the weapons advertised officially as Energon weapons. There were also the more static and traditional rifles and missile launchers packed with the larger Energon toys, even these weapons usually still had multiple posts and ports, including Mini-Con posts and ports, allowing them to be merged with other Energon weapons. As the series progressed, a third type of energon weapon was added: the multi-configuration weapons included with the Energon quintro-combiners, which were designed to be feet and hands for the large Energon combiner robots, as well as weapons for the component robots.

Energon was really the first Transformers toy line to emphasise and advertise swapping and trading weapons as a pattern of play, despite the fact that Transformers toy lines had been capable of this play pattern since nearly the beginning. Over in Japan, this was emphasised even more with energon weapons from Omnibots given away, sold as separate units, or included as bonuses with redecos.

2004

MINI-CONS

Not many Mini-Cons were produced during Energon. There was only one entirely new team and a handful of redecos. They are all 5 mm-compatible, as is standard for Mini-Cons. Those Mini-Cons of special interest are listed below.

• Skyboom and the Energon Saber — Retooled from Armada's Star Saber, they have the same basic compatibilities.
• Knock Out — A redeco of Armada Rollout with all the same compatibilities.
• Payload, Sky Blast and the Requiem Blaster — A redeco of the Requiem Blaster from Armada, with the same basic compatibilities.

AUTOBOTS

The listing below describes, for the most part, the individual robots. Keep in mind that each toy also came with a gun, usually a transluscent energon weapon with multiple ports and pegs, and even Mini-con compatibility. Even toys without Mini-con plugs of their own often had them on their guns.

• The Omnicons, Offshoot, Signal Flare, Skyblast, Strongarm, and his redeco Energon Strongarm — The Omnicons were Basic-sized toys, the first toys featured at this price point to have 5 mm fists. Each came with an energon weapon, as described above, made up of several components, and an energon star meant to fit over spark crystal of Energon toys.

• Arcee — Arcee is the only Omnicon without 5 mm fists. She has 5 mm post holes in her arms meant to stand in for 5 mm fists, but her actual hands are eenie-weenie.

• Sky Shadow, Treadshot, Terradive and Windrazor — The limb components of Superion Maximus. They had standard 5 mm compatibility and unique transformable energon weapons that became "hands" and "feet" for Superion Maximus.

• Downshift — Downshift features a spoiler that becomes a unique platform for holding both his guns or any other energon weapons.
• Hot Shot, Energon Hot Shot and Prowl
• Inferno, Roadblock and Rodimus — In addition to standard Energon compatibility, these toys retain the Mini-Con ports from Transformers: Armada. Rodimus has one, Inferno and Roadblock each have two.
• Tow-Line — Unlike the other Combat-Class Energon toys, Tow-Line was actually made up of two components which combine to form his vehicle mode, a robot and a battle platform. The robot is fairly standard for Energon toys, with many post holes for 5 mm weapons of all sorts, some of them in rather unusual places. The battle platform in particular, though, is basically designed as a showcase for Energon weapons, making a perfect platform for building insane or over-the-top energon weapon combinations.

• Beachcomber and Cliffjumper — This mould has a Mini-con port on its shoulder pad. Unlike most other Energon Autobots their weapons, while 5 mm compatible, are not designed after the Energon weapon style. They don't have any extra posts or ports, and aren't made of translucent plastics. They're just simple hand-held guns.
• Ironhide and Energon Ironhide — One of a handful of Energon moulds without its own hand-held rifle. Has a Mini-Con port on his right forearm.
• Jetfire and Overcast — The Mini-Con ports on their shuttle mode become their toes in robot mode so... uhhh... good luck with that. The rifle that comes with this mould, despite being translucent, is not effective as an Energon weapon. It has two gun posts, but no other compatibility. It may have been intended to, though. On top of the rifle is a piece of moulding that looks exactly like a Mini-Con post, including their unique base... but it's teeny tiny and undersized.

• Treadbolt — A redeco of Armada Scavenger with all his compatibilities.
• Wing Saber — He has no hand-held rifle, but he does have a Mini-Con port on his left forearm.

• Bulkhead and Quickstrike, Landmine and Landquake — Both these moulds are littered with 5 mm ports and pegs. The Bulkhead mould also has a Mini-Con peg on his helicopter tail, while the Landmine mould has two Mini-Con ports on his large cannon for his Brute mode.

• Ultra Magnus — A redeco of Armada Overload.

• Optimus Prime — Prime has 4 Mini-Con pegs in vehicle mode: 2 on his trailer, and 2 on his cab. In robot mode his trailer becomes a base and is still Mini-Con compatible, but the Mini-Con ports are hidden in Prime's robot mode, sadly. Prime's gun is just a standard rifle, not an energon weapon.
• Omega Sentinel and Omega Supreme — This mould has 4 Mini-Con ports on his shoulders, front and back, and a handful of 5 mm posts. Still, considering its size it's not enormously versatile at using 5 mm compatible weapons.

DECEPTICONS

• Battle Ravage, Command Ravage, Cruellock, Doom-Lock and Insecticon — All the Energon Terrorcons have 5 mm fists as standard. In addition to his Energon weapon Ravage also has a tail mace.
• Divebomb — Divebomb's wing-mounted weapons come in two variants. The first variant has only one 5 mm post on the base of the two-part weapon. The second variant was retooled to have two posts, one at either end of his weapon.
• Bonecrusher, Duststorm, Sledge, and Wideload — The limbs of Constructicon Maximus. Each of them has 5 mm fists as standard. The Duststorm/Wideload mould also has a Mini-Con peg on its crane arm.
• Steamhammer — Steamhammer loves Mini-Cons. In both robot and vehicle modes he has 5 Mini-Con posts. That's a lot, even for an Energon toy, allowing him to hold a partner Mini-Con, an entire Mini-Con team and have one left over for an Energon weapon. Too bad he doesn't have a Mini-Con partner. (Oh yeah, he's got a bunch of 5 mm post holes too.)
• Constructicon Maximus — He retains six Mini-Con pegs, four from Steamhammer and two from Dust Storm and Wideload, though Steamhammer's aren't particularly accessible. He doesn't have 5 mm peg hole hands.
• Blackout, Stormcloud — This mould has two 5 mm posts on each arm in robot mode.
• Blight, Kickback — The tank mould technically has three Mini-con ports on his weapon, though only one is accessible in vehicle mode, and in robot mode one of them has to form the handle for the gun. In practical terms you're probably only going to get one Mini-con on there.
• Barricade — Barricade likes Mini-cons too, but not as much as Steamhammer. He's got three Mini-con posts in robot mode and two in vehicle mode.
• Bruticus Maximus — Thanks to Barricade he has two Mini-con ports on his thighs. He doesn't have 5 mm post holes for hands, but he does have Mini-con ports on his thumbs when using the tank as an arm, or on his heels if using the tank as a leg.
• Demolishor — In addition to his 5 mm fists he has four Mini-con posts, though generally speaking only two are accessible in either mode. Because the posts are on a hinged piece it is possible to expose and use all four at once. His missiles can also fit into his hands, but aren't particularly effective because he holds them at about the midpoint on the missile.
• Starscream and Energon Starscream — Based conceptually on the G2 Smokescreen mould, unlike that mould Starscream is highly 5 mm compatible. He has a crazy Energon weapon, with multiple configurations and mini-con ports, so the gun section of the weapon can be used a Mini-con. He has Mini-con pegs on his wings that are accessible in both modes. Oh yeah, and the heads of his missiles are 5 mm, so he can use them as swords if he gets tired of his giant Energon sword.
• Rapid Run — A redeco of Armada Sideways.
• Sharkticon, Slugslinger, Snow Cat — In addition to 5 mm fists, they all have Mini-con ports on the kibble on their forearms. Snow Cat only has a port on his left arm.
• Dreadwing and Mirage — This mould loves 5 mm pegs. Including fists each arm has three 5 mm peg holes, as well as a Mini-con port. The toy's missiles are also 5 mm wide, letting him hold them as swords. Oh yeah, and he has 5 mm posts on the insides of his knees.
• Shockblast and Six Shot — Doesn't have traditional hands, but has plenty of 5 mm post holes.
• Scorponok — Doesn't have traditional hands, but has plenty of 5 mm post holes. Has some very inaccessible Mini-con pegs on the missile launchers on his claws.
• Tidal Wave — An awesome redeco of Armada Tidal Wave.
• Galvatron and Megatron — This same basic design was released twice at two different size scales. They're all 5 mm compatible. The larger version has 6 Mini-con ports in jet mode, and two in robot mode. The tank accessory also features a Mini-con port on the turret's hatch, exactly where such a post was located on the Armada Megatron figure it was based on. The tank also has four 5 mm post holes on its underside, which are used to dock the tank to the jet.
• Alpha Quintesson — While he doesn't transform, Alpha Quintesson is positively brimming with 5 mm posts. He has a 5 mm post missile launcher too.

Cybertron

While Transformers Cybertron continued the widespread 5 mm compatibility seen in Armada and Energon, it was in a more low-key form, as the central gimmick of Cyber Keys had nothing to do with 5 mm posts whatsoever. Mini-Con ports became rare again, though not unheard of — the focus was now almost entirely on weapons.

2005

MINI-CONS

Ichibi's added post actually removes the original Powerlinx function. Whoops.

Mini-Cons were rare at the beginning of Cybertron, consisting of Safeguard and the Recon Mini-Con Team. As time went on, however, the line introduced a few more teams, a series of Mini-Con two-packs redecoed from Armada and Energon molds, and an assortment of Mini-Cons both old and new as pack-in bonuses. Naturally, these all retained standard Powerlinking capability; listed below are Mini-Cons with additional abilities beyond that.

• Checkpoint, Stripmine, and Deepdive — Each of these Mini-Cons sports a 5 mm post. Stripmine and Deepdive's posts are hollow.
• Scrap Iron, Backblast, and Blastcharge — Another redeco of the Requiem Blaster, with everything that implies.
• Downshift, Dirt Boss, and Mirage — Redecoes of the Race Team, with all the same compatibility.
• Bulge, Graviton, and Quasar — Redecoes of the Emergency Mini-Con Team. Bulge (copter) was retooled to add a 5 mm post to his tail section, and Graviton (crash truck) had a 5 mm peg glued into one of his Powerlinx sockets. Both of these additions were to make their weapon modes hand-held.
• Hyakurai, Ichibi, and Mugen — Retools of the Air Military Mini-Con Team. Each one was given 5 mm pegs to make their weapon modes hand-held (even though their main partner, Wing Saber, didn't have 5 mm-compatible hands).

AUTOBOTS

• Vector Prime — He is from an earlier, apparently Armada-esque age and his form reflects that. He is here to sport multiple Mini-Con posts, 5 mm fistholes, and a 5 mm-compatible sword. He is not here to blend.
• Longrack — A retooled Armada Hoist, Longrack still sports a 5 mm post. (Blurr does not.)
• Red Alert — Has one 5 mm hand, and one gun-hand which is a 5 mm post, with "hammer" and "claw" attachments that fit on the end.
• Clocker, Swerve — Clocker has a 5 mm gun (with two pegs, side by side) and fists to hold it... and also has dual exhaust pipe accessories that attach (to the undersides of his fists, actually) using hollow 5 mm posts.
• Hot Shot, Excellion, Landmine, Scattorshot, Jetfire, Override, Override GTS, Armorhide, Brakedown, Brakedown GTS, Crosswise, Smokescreen, Downshift — All feature 5 mm weapons, fists, and vehicle mode mounting points.
• Hightail — His trombone gun has a 5 mm post, and he has the fists to hold it.
• Overhaul, Evac — Though they lack any handheld weapons of their own, these toys have 5 mm fists.
• Quickmix, Cybertron Defense Hot Shot, Cybertron Defense Red Alert, and Cybertron Defense Scattorshot — Quickmix and all three members of the Cybertron Defense Team have 5 mm-compatible fists and accessories, and bear hollow 5 mm posts for mounting Mini-Cons.
• Metroplex — Metroplex is covered in hollow 5 mm posts, with a total of 14.
• Optimus Prime (Deluxe trukk) — A redeco of the Armada Super-Con Optimus Prime mold with the same functionality. Instead of Over-Run, he includes a special Cyber Key that has the same hole-with-a-post as a Mini-Con, making it capable of attaching to any hollow 5 mm post.
• Optimus Prime and Ultra Magnus — Redecoes of the Robots in Disguise versions, with all that that implies.

DECEPTICONS

• Buzzsaw and Runamuck — Retooled versions of Armada Cyclonus and Side Swipe. Buzzsaw retains most of Cyclonus's compatibility, but has lost the posts on his missile launchers. Runamuck, meanwhile, has lost Sideswipe's accessories in favor of a new 5 mm gun.
• Megatron, Galvatron, Ransack, Ransack GTS, Starscream, Hardtop, Swindle, Lugnutz, and Soundwave — All these figures have 5 mm hands and weapons.
• Crumplezone, Dark Crumplezone, Thundercracker, Skywarp, Dirt Boss, Mudflap, and Brushguard — These figures have 5 mm hands, though they include no compatible accessories.
• Dark Scorponok — A retooled Scorponok that retains the Energon toy's features and adds Cyber Key compatibility.
• Thunderblast — Like Arcee before her, Thunderblast's hands are too small and girly for 5 mm holes, so she has them further up on her forearms instead. Her weapon is 5 mm-compatible.
• Menasor — Like Metroplex, Menasor likes Mini-Cons.
• Cannonball — A redeco of Red Alert with the same compatibility.
• Scrapmetal — All Scrapmetals have 5 mm fists, and in an undocumented feature, their flip-out blades can be hand-held.
• Demolishor — A redeco of Armada Demolishor with the same features. Instead of Blackout, he includes a Cyber Key with a Mini-Con-style 5 mm hole on the back, similar to the deluxe Optimus Prime's.

OTHER

• Primus — Like Unicron before him, Primus sports an assortment of hollow 5 mm posts. His total is far lower (nine), but in Primus's defense, most of Unicron's are on his ring.
• Sideways and Unicron — Both feature 5 mm fists and accessories.

Classics

Classics brought back many old Transformers characters with new toys, and most of those toys were 5 mm compatible. It also introduced yet more Mini-Cons, though hollow 5 mm posts are few and far between in Classics.

Transformers (2007)

The live-action movie toyline mostly eschewed the use of the 5 mm system, in part because the integrated nature of the characters' weapons meant a low number of handheld accessories overall. Nevertheless, the reuse of various molds from the previous few years ensured that 5 mm posts continued to appear.

Animated

Transformers Animated had few 5 mm-compatible toys, but they existed.

2008

AUTOBOTS

• Cybertron Mode Optimus Prime - His axe and shield have 5 mm posts, and therefore his hands are also compatible with them.
• Voyager Class Optimus Prime - Both his axe and his water gun use the standard 5 mm posts, and therefore his hands are also compatible.
• The Battle Begins Optimus Prime - His axe uses the 5 mm post for its handle, and his hands are compatible with them... as is the hole in his buttocks.
• Jazz - His hands are open with a 5 mm groove in them to hold such accessories.
• Sentinel Prime - Both his shield and lance sport 5 mm posts, and his hands are compatible. However, the fingers are sculpted with a gap over the 5 mm holes, so accessories with smaller posts can only be held from the bottom of his hands.

DECEPTICONS

• Lugnut - The inside of his robot mode hands sport 5 mm posts, which can also double as a Mini-Con port. His mace also has a 5 mm hole in it.
• Swindle — Appropriately enough, Swindle is equipped with a large cannon on a 5 mm post, and has two 5 mm holes with which to use it.
• Leader Class Megatron - His swords are mounted on 5 mm handles, and his hands therefore sport 5 mm holes.
• Shadow Blade Megatron - Being a redeco of Leader Class Megatron, he carries over the same 5 mm compatibility.
• Shockwave - His gun/crane uses a 5 mm post, so the holes in his forearms and back are compatible with other weapons.

2009

AUTOBOTS

• Freeway Jazz - Being a redeco of Jazz, he shares the same 5 mm-holed hands.

DECEPTICONS

• Atomic Lugnut - Being a redeco of Lugnut, Atomic Lugnut sports the same posts in his hands, and the same hole on his mace.
• Shockwave Vs. Bumblebee - The Shockwave in this pack, being a redeco of the previous Shockwave, has the same post/ports.

2010

AUTOBOTS

• Arcee - Arcee's hands can hold 5 mm post weapons. However, her weapons are slightly thicker. This resulted in many a broken thumb.
• Rodimus Minor - The tabs on his bow are 5 mm wide.

2011

AUTOBOTS

• Minerva - Being a redeco of Arcee, she shares the same 5 mm-holed hands. But continue to be careful with her slaggin' thumbs!
• Sideswipe - Being a redeco of Breakdown, Sideswipe shares the 5 mm bow tabs.

DECEPTICONS

• Dead End - Being a redeco of Jazz, he shares the same 5 mm-holed hands.
• Drag Strip - Being a redeco of Arcee, she shares the same 5 mm-holed hands. But continue to be careful with the swords!
• Motormaster - Being a retool of Voyager Class Optimus Prime, his axe and cannon use the same 5 mm posts, and the hands use the same 5 mm holes.
• Toxitron - Being a redeco of Voyager Class Optimus Prime, his axe and cannon use the same 5 mm posts, and the hands use the same 5 mm holes.
• Breakdown - Being a retool of Rodimus Minor, Breakdown shares the same 5 mm tabs on his bow.

Universe (2008)

Following in the footsteps of Classics, Universe toys nearly always featured 5 mm fists and accessories.

Revenge of the Fallen

The toys for the Revenge of the Fallen movie initially returned to the design principles of the previous live-action movie, but in time, 5 mm accessories began to creep back in. This line also introduced an alternate system of interchangeable accessories, the C joint.

Generations

Once again, Generations typically followed the example of Classics and Universe, featuring widespread 5 mm compatibility.

Power Core Combiners

Much like Armada and Energon, Power Core Combiners heavily emphasized compatibility between different toys. The main focus of the line, the "combination" suggested by the title, was a series of "Commander" figures who could combine with interchangeable drone vehicles in a fashion similar to the Special Teams. Commanders were sold either with sets of drones or in smaller packs with Mini-Cons. These Mini-Cons were also designed to have weapon modes, using 5 mm posts, and as such 5 mm fists proliferated. The Commander figures also featured hollow 5 mm posts for mounting the Mini-Cons, and the drones all featured hollow 5 mm posts as well, leading to insanity.

2010

MINI-CONS

In additional to the usual capabilities of Mini-Cons, every PCC Mini-Con has at least one 5 mm post, usually hollow, which enables it to be handheld. Special cases are listed below.

• Chopster, Razorbeam — The axe Mini-Cons unfortunately have a narrower segment below the 5 mm grip, similar to double-posted weapons, and as such they cannot be held by toys with shallower fist holes (ironically including Darkstream). The post is also solid, so it can only connect to empty 5 mm holes.
• Backwind, Beacon, and Pinpoint — These three have empty 5 mm holes rather than the usual Mini-Con ports. This prevents them from activating Powerlinx gimmicks, but allows them to attach to ordinary 5 mm posts, not just hollow ones.

AUTOBOTS

The Rallybots feature "hidden" 5 mm Powerlinx plugs. Neat! Pity about everything else about them.

• Skyburst — One hollow post on his back, and shallow 5 mm fists.
  • Aerialbots — All four drones have hollow 5 mm posts on the top, though the Fighter Jet's is not really useful in combined mode. The helicopters' posts are on top of their rotors, and as such any Mini-Cons or weapons attached there will spin freely.
• Huffer — For unknown reasons, Huffer has fist holes, but they are far too small to hold 5 mm posts. He has a hollow 5 mm post on his right forearm to make up for this, and another flip-out post on his chest.
• Searchlight — Searchlight is absurdly 5 mm-compatible for a toy of his size. In addition to the usual 5 mm fists, he has 5 mm holes in the sides of his forearms, meant for attaching his vehicle mode rotors. He also has the flip-out hollow chest post typical of PCC Commander molds originating in two-packs, and a second hollow post on what becomes the underside of his cockpit in vehicle mode. As implied by the forearm holes, his rotors are separate accessories that can connect to any 5 mm peghole (including the one on Backwind's chest).
• Double Clutch — He has a single hollow post on a hinged panel, which is normally concealed in most modes but can be folded out. For holding weapons he has sideways holes on the inside of his forearms, which are awkward in robot mode but can be used more effectively as shoulder weapon mounts in his torso mode. They're shallow, but with their positioning you probably wouldn't want to give him Chopster anyway.
  • Rallybots — Each Rallybot has a hollow post that can fold away, located on the rear bumper of the Race Car and on top of the others. Interestingly, the Street Racer reveals a second post in leg mode, which is necessary since the vehicle mode post ends up on the bottom of the foot.
• Leadfoot — Like Double Clutch, Leadfoot has sideways forearm holes instead of fists. Unlike Double Clutch and basically everyone else ever, both of his hollow posts are flip-out posts for chest armor, one (normally concealed under his windshield) for his robot chest and one for his combined chest. Both can be used in vehicle mode as well.
• Stakeout — A redeco of Smolder with the same features.
  • Protectobots — Redecos of two Aerialbots (Chopper and Fighter Jet) and two Combaticons (APC and Tank).
• Steelshot — A redeco of Bombshock with the same features.
• Grimstone — Grimstone has shallow fists and a single 5 mm post on his tail (in robot mode, his back).
  • Dinobots — The Parasaurolophus drone has two side-mounted Mini-Con posts. The others are more or less standard.
• Heavytread — In addition to the usual flip-out chest post and 5 mm hands (irregularly-shaped but usable), Heavytread has a 5 mm peghole on top of his vehicle mode near the forward right corner. This hole is usable in all three modes, ending up approximately on his wrist in robot mode.
• Salvage — A redeco of Mudslinger with the same compatibility. Since he has 5 mm fists, Bomb-Burst gets the official weapon mode that's technically a fanmode on Chainclaw.

DECEPTICONS

Sledge and his weird chest-peg assembly.

• Bombshock — Bombshock has two hollow posts quite close to each other: one is on top of his turret (ending up on the back of his torso mode head), while the other is between his cannons. Both end up on his back in robot mode, in varying configurations depending on how his kibble is arranged. Like his wavemate Skyburst, he has shallow 5 mm fists, so no axes for him.
  • Combaticons — All four drones have top-mounted posts which are accessible in both modes, though because of the APC's transformation, Mini-Cons attached to it in combined mode will appear to extend from the robot's knee.
• Smolder - Smolder has 5 mm fists, and a flip-out hollow 5 mm post on his chest. He has a second hollow post on the roof of his vehicle mode, which in his other modes ends up in an awkward but usable position on the back (robot mode) or front (torso mode) of his right shoulder.
• Mudslinger - Mudslinger has a 5 mm post near the back of his vehicle mode, accessible in all three modes... which ends up on the front of his left knee in robot mode, and the inside of his right knee in torso mode. Good luck making use of that. At least he has 5 mm fists.
  • Destructicons — All four Destructicons have top-mounted posts that remain accessible in limb mode. The Heavy Hauler's post can fold away like those of the Rallybots.
• Icepick — Oddly enough for the PCC line, Icepick has no 5 mm pegholes at all, with the effect that Chainclaw's 5 mm weapon mode was omitted from the instructions. His compatibility consists of a hollow 5 mm post on his right shoulder and a fold-out one on his chest, both usable in all three modes.
• Sledge — Like his wavemates, Sledge is odd: he has shallow wrist holes (this time located under his forearms) instead of fists, and unlike his fellow two-pack-originated Commanders, he has no flip-out posts at all (maybe Leadfoot stole his?). Instead he has a single hollow post on his chest that serves all three modes, and another on his shovel.
• Crankcase — A redeco of Huffer with the same abilities.
  • Destrons — Redecos of two Aerialbots (Recon Plane and Combat Helicopter) and two Combaticons (Missile Carrier and Armored Car).
• Darkstream — A redeco of Skyburst, incapable of any interaction with Razorbeam other than wearing him on his back.
• Windburn — A redeco of Searchlight, retaining his capabilities.
• Steamhammer — Steamhammer is unusual among five-pack-originated Commanders: his torso mode has a hollow 5 mm post on his chest! This post is basically inaccessible in his other modes, so he has a second one on his roof, which in robot mode is on a block hanging awkwardly from his elbow.
  • Constructicons — The Constructicons' posts are all well-placed, with no particular unusual qualities.
• Skyhammer —
• Over-Run — A redeco of Leadfoot with the same abilities.
  • Stunticons — Redecos of two Rallybots (Race Car and Tuner) and two Destructicons (Armored Truck and Armored Junker).
• Undertow — Similar to Sledge, Undertow has one fixed hollow 5 mm post, accessible in all modes.

Transformers (2010)

The 2010 Transformers toyline continued to make widespread use of 5 mm posts and holes (though perhaps not as widespread as some previous lines). C joints proliferated as well, leading to a veritable golden age of interchangeable weapons.

Dark of the Moon

Ya feelin' lucky, pardner?

When it came to Dark of the Moon, the smaller and larger size classes were respectively split between the Cyberverse and MechTech brandings. While C joint compatibility was further established between the two, the 5 mm post absolutely flourished.

Nearly all of the MechTech toys use 5 mm posts for their MechTech weapons, with the line also emulating the Stealth Force attack modes that were featured in the film. As a result, the toys come with a very large number of ports, hidden or otherwise, for the weapons to peg into for each figure. The larger figures even have MechTech ports on the weapons themselves, and the packaging blurb encourages the user to create "new weapons" by combining then.

This line also introduced a minor innovation: self-covering pegholes. Many MechTech toys have 5 mm holes that contain circular plugs on springs. Inserting a weapon handle depresses the plug; when the weapon is removed, the spring pushes it back up to sit flush with surrounding panels.

Each of the Cyberverse "Action Sets" also contains at least a single, large, removable, spring-loaded (but not always missile-firing) weapon integrated into the set itself, allowing interchangeability between the weapons of both Cyberverse Action Sets and MechTech figures. The Cyberverse Ark, in particular, features six weapons (one functional) that are mounted via 5 mm posts and holes.

Prime

Arms Microns can be combined into some truly ridiculous weapons.

The Prime toyline use 5 mm pegs and ports for most of its weapons. Soundwave's deployers also use 5 mm pegs and ports to attach to him.

The Japanese version of the line takes this to a higher level though, with the "Arms Micron" play-pattern. All non-Cyberverse toys in the line have been retooled to include several extra 5 mm sockets, and include a snap-together Mini-Con partner that transforms into some form of weapon. There are also numerous Arms Microns sold as individuals. The Microns have multiple 5 mm posts and sockets, and can be combined to form "Combo Weapons" like the Nebula Scythe, and "Super Combo Weapons" like the Star Saber and the Galaxy Launcher. While they will occasionally highlight these specific named combinations, the marketing for Prime in Japan heavily plays up the idea of just going nuts with your own custom Micron combinations.

Construct-Bots

The Construct-Bots toyline is primarily based on 5 mm pegs for interchangeability of armor and weapons. Even the faction symbols are on 5 mm pegs!

Robots in Disguise (2015)

Similarly to Prime, its successor series also uses 5 mm post near-universally. And much like the Arms Micron series for the Japanese release of Prime, this series includes Weaponizer Mini-Cons which include at least one post to allow them to be held or mounted on other figures in the line. Many of them have multiple posts, and one mold in particular (Lancelon) has one of those posts as a double post, with a 3mm post extending from the one on his back. However, they do not appear to be meant to combine the same way that Arms Microns are.

War for Cybertron trilogy

The C.O.M.B.A.T. System consists of a standardized set of 5 mm ports across most figures. The Weaponizers introduced in the trilogy's Siege portion, and their successors the Modulators from Earthrise, and Fossilizers from Kingdom are all Deluxe-sized figures that can form armor and weaponry for C.O.M.B.A.T.-equipped toys. Micromasters, making a return from G1, can combine to form Mini-Con-esque "weapon" modes, along with some of them having 5mm holes that allow them to act as Mini-Cons. Battle Masters, much like the Targetmasters of old, can also transform into dedicated weapons usable for larger Transformers.

Legacy

The 5mm port play pattern continued into the War For Cybertron trilogy's successor Legacy and its subline imprints of Evolution and United. Evolution featured Weaponizer styled Junkions who can be disassembled into armor and weapons with the added benefit of not needing to be transformed via partsforming, as well as the first Voyager to use the format, while United featured the Armorizer subgroup: the result of combining the weaponizer format with Daira rock monsters and Rock Lords.

All the while, figs retain some degree of 5mm posts to use this feature.

Age of the Primes

Micronus Prime is an odd case, as the figure himself does not utilize the Weaponizer format; rather, the large unicycle vehicle he comes with does, and does need to be dismantled to transform, unlike the Legacy Junkions and Armorizers. Amalgamous Prime, meanwhile, does not need to be disassembled for conversion into his spider-tank mode (aside from the tank barrel/Scythe), but does still disassemble at the 5mm ports to be rebuilt into whatever your imagination can concoct (which is obviously the figure’s main draw). The line's 2026 offerings also include two Legacy Junkion redecoes, Jalopy and Animated Wreck-Gar. All figures in the line still use 5mm posts and are thus compatible with them.

Notes

• Due to Takara's Brave series toys sharing many of the same designers from the latter days of G1, a great many of the figures utilize 5 mm weaponry pegs. This, of course, can give even the smallest 5 mm compatible Transformer the ability to carry 5" chrome swords and gigantic guns.
• Other Takara lines have also used the 5 mm pegs, including Battle Beasts transforming playsets and the Robolinks toy line.
• The 5 mm post/hole system is also used extensively by companies such as Bandai and Tomy. The Machine Robo Rescue (not to be confused with the trademark-interfering Machine Robot Rescue from Universe Ratchet and Inferno's packages) and Zoid Blox lines all utilize it.
• While LEGO toys do not make use of 5 mm posts in and of themselves, they frequently use a style of hollow connector pin that coincidentally fits snugly into 5 mm holes. One particularly common part consists entirely of two such pins back-to-back, making it a workable add-on handle if you want your Mini-Cons to be hand-held. However, there can be danger of the piece snapping when trying to get it into a Powerlinx post, due to the differing widths of LEGO elements.