Door Hardware: How to Maintain Cylinders
The cylinder is the part of the door lock that contains the key plug. Its main components are the cylinder body, the plug containing the keyway, and the pins, which vary in length. A unique pin-length sequence customizes each lock so only the same profile ground into a key can open that lock.
Master keys open a group of locks. There also are grand master, great-grand master, and great-great-grand master keys that open subsequently higher levels of lock groups. Construction master keys allow access to a group of locks only for the construction period. These locks become inoperative when the tenant or owner takes occupancy, protecting the security of the regular, permanent system.
The primary maintenance requirement for lock cylinders is application of a high-quality, detergent-type lubricant once a year. This treatment will prevent sticking resulting from the accumulation of dust and dirt, but it will not prevent jamming due to foreign objects forced into the keyway.
Cold weather or large amounts of dust or dirt might require more frequent, light applications of lubricant. The best way to establish frequency for such conditions is through experience. Try once at the beginning of the extreme condition period and adjust the frequency if that is not sufficient.