An interchangeable core or IC is an adaptable locking key cylinder. Unlike a standard key cylinder, which is accessible for combinating only via locking device disassembly, an interchangeable mechanism relies upon a specialized "control" key for insertion and extraction of the essential (or "core") combinating components. "Small format" interchangeable cores are in a figure-eight shape that is standard among lock manufacturers. "Large format" interchangeable cores are of varying sizes.Interchangeable cores can be extracted from one lock type (bored cylindrical lock, mortise lock, padlock and so forth) and then installed into another without requiring the removal or disassembly of any single component. These units are readily adapted for master keying systems and can be set up with spare co