Cylinder: The cylinder is the name for the locking mechanism. This contains the pins, springs, keyway and tailpiece.
Housing: The housing is a metal shrouding which encases the working parts of the lock.
Plug or core: The plug or core is the rotating mechanism. The plug contains the keyway, where the key is inserted, as well as the bottom pins. During a rekey the plug is extracted from the housing.
Keyway: is located on the front of the plug. This is where the key is inserted.
Top Chamber: The top chamber is the vertical protrusion along the top of the cylinder. This contains the top pins and springs.
Top springs: Top springs sit in the top chamber applying a downward pressure on the top pins.
Top Pins: Top pins sit in the top chamber between the top springs and bottom pins.
Bottom pins: Bottom pins sit in the plug of the cylinder. They have many different lengths, which match according to the depths of the cuts on the key. When the lock is engaged, the top pins and bottom pins block the sheer line, preventing the plug from spinning.
Sheer line: When the proper key is inserted into the keyway a sheer line is created between the top and bottom pins, enabling the core to spin.
