Deimos

Deimos, known also as the Steel Forge, is formerly a moon of Mars which serves as a major Forge World for the Daemon-hunting Grey Knights Space Marine Chapter, the Chamber Militant of the Inquisition's Ordo Malleus. This Adeptus Mechanicus realm is devoted exclusively to providing the Chapter with arms, munitions and war machines. In theory, the Grey Knights have access to any pattern of war machine ever wrought by the hand of the servants of the Machine God, but in practise they limit the use of armoured transports to the mighty Land Raider and a few other key fighting vehicles.

History
The war needs of the Grey Knights call for a constant supply of ammunition and ordnance. Long ago the Chapter made alliance with the Adeptus Mechanicus and as part of their bargain were gifted with the forge world of Deimos. Formerly one of the moons of Mars, the planetoid was dragged across the system to hang in the sky above the Grey Knights' Chapter Home World of Titan, its mass mined and converted until it was more star fort than celestial body. The Tech-Priests and servitors of Deimos serve the Grey Knights alone, crafting everything from bolters and bolt shells to Stormravens and Land Raiders.

Only the Nemesis force weaponry is created in the citadel by the Grey Knights Techmarines themselves; all other materiel is ferried down from Deimos in an endless stream of heavily guarded transports. Servitors oversee the packing and transportation of everything destined for Titan, loading consignments in utmost secrecy to ensure that no one, not even the tech-magos of Deimos know the extent of the Grey Knights arsenal. The same servitors are then mind-wiped before their return to Deimos, lest the enemies of the Imperium were ever to dissect their shrivelled brains.

Relics

 * Fury of Deimos - When the moon of Deimos was gifted to Titan by the Adeptus Mechanicus, it carried with it a ship loaded with some of the finest weapons the Imperium has ever created. Among them was the Storm Bolter Fury of Deimos, a weapon crafted by the first Fabricator-General. Superior in range, accuracy, rate of fire and reliability than a normal storm bolter, it is a relic whose secrets have long been forgotten.