Locks

Locks are devices that restrict access to doors, containers, or other enclosures by requiring a specific credential to retract a bolt or latch. The basic purpose is to deter unauthorized entry while allowing authorized access when the proper key, combination, or electronic signal is provided.

Mechanical locks rely on mechanical components such as pins, springs, and a keyed cylinder to prevent rotation unless the correct key aligns the internal parts. Common forms include padlocks, deadbolts, cylindrical locks, mortise locks, and rim locks. Electronic and smart locks use keypads, proximity cards, biometric sensors, or wireless communication to authorize operation, often integrating with building management systems.

Key mechanisms include pin-tumbler, lever, warded, and disc or radial-lock designs. Security features such as hardened steel components, anti-pick pins, anti-drill plates, and options for rekeying are used to improve resistance to tampering; locks are rated by standards such as ANSI/BHMA grades.

Historically, locks evolved from simple wooden devices and warded mechanisms to robust metal designs, with pin-tumbler systems becoming dominant in the 19th century. Today locks are used on doors, safes, cabinets, and outdoor enclosures, with padlocks serving portable security and smart locks enabling access control and monitoring. Regular maintenance includes lubrication, key management, and timely replacement of worn parts.