The Hammer Factory is a forge within the St. Edgar's Church cathedral complex. Primarily used by the resident Hammerites to construct blessed Hammers and other tools. It is explored in detail in Thief: Deadly Shadows, as Garrett makes use of its various machinery in order to steal the Builder's Chalice, a sacred "relic" stored within its premises.
The factory is also home to the electrical power system, and powers the entire cathedral complex.
- Main article: Builder's Chalice
The factory holds and protects the most sacred object in the cathedral, the Builder's Chalice "relic", actually an ancient artifact created by the Ancient Keepers.
It is kept in a caged cell high above reach, along with other holy objects. (pictured right). This cell is located within a well-guarded room, with two entrances. Secured by unique and sophisticated machinery, one needs the Holy Symbol and Stamped Gear in order to activate it.
The Stamping Machine is used to transform an Unstamped Gear into a Stamped Gear, which can then be used to activate the Chalice's security system. When an Unstamped Gear is placed into the stamping machine, it automatically starts the electrical system, rotating the receptacle and passing heavy electrical current through the gear, thereby changing its shape, transforming it into a Stamped Gear.