Forge of Solus Prime

Apparently not pulled out of subspace.

The Forge of Solus Prime is the symbol of office of the master-artificer of the Thirteen. Oddly, it is not actually a forge in the classic sense, but rather a hammer the size of which suggests that Solus Prime and her brothers towered over modern Cybertronians. This hammer was used to craft all other artifacts of the Thirteen, and is noted to be one of the few things which could craft the core components of a Cybertronian body from scratch. It is largely inert when not in the hands of a Prime, but that doesn't mean it can't pack a slagging huge whallop. The thing is so heavy that only Optimus Prime and Megatron can carry it without any difficulty.

Fiction

Prime cartoon

The Forge was wielded by Solus Prime as the Thirteen battled Unicron. One Shall Rise, Part 1

Before the Great War, the Forge of Solus Prime was kept in the Vaults of Iacon, but was hidden on Earth to keep it out of the wrong hands. Millions of years later its location was decoded by the amnesiac Optimus Prime at the behest of Megatron. The Decepticon warlord later sent Breakdown and Knock Out to retrieve it. Breakdown managed to mostly unearth the titanic hammer, but ultimately was denied by Bulkhead who proceeded to wipe the floor with the hapless Decepticon, aided by the Forge. Megatron's timely arrival via GroundBridge wrested the Forge from Bulkhead's servos, but upon returning to the Nemesis, the Decepticon leader found that the hammer was nothing but a cudgel unless held by a Prime. Operation Bumblebee, Part 2

Plot details for Alpha/Omega follow. Spoilers have expired, you may remove this tag

After Optimus got hold of the Star Saber, Megatron resorted to drastic measures—returning to Cybertron, he took the arm of a Prime and had it grafted to himself, granting him the use of the Forge. He used the Forge to create the Dark Star Saber from a piece of Dark Energon, and the new sword proved more than a match for the Star Saber. Alpha/Omega

Notes

• Suns are capable of forging any raw element (up to iron) under the right conditions, so it's fitting that the Forge of Solus Prime can forge anything FROM raw elements under the right conditions (Primehood).