LOCKS AND HARDWARE
A. Bolts and Latches
Spring latches are beveled-edge latches which are spring- operated and automatically snap into position when the door is closed. This latch offers security for situations where the threat and risk assessment indicates threats from opportunists only.
Dead latches are identical to the standard spring latch except that when the door is shut, the spring action is locked by a pin- operated lever beside the bolt. The pin is depressed by part of the striker plate when the door is shut. This latch offers security only when the threat and risk assessment does not indicate a threat of door frame spreading.
Deadbolts are usually operated by a key or thumb turn and do not incorporate a spring function. This type of bolt, properly fitted, will withstand most amateur attempts at prying. A hardened steel deadbolt with a 25.4 mm (1.0″) throw offers excellent security if it is installed in a high quality door and frame in a strong wall assembly.
B. Lock Bodies
Bored, cylindrical or tubular locks are installed in a circular hole in the door. They are easy to install, inexpensive and easy to use. A bored lock may employ any type of latch or bolt and may be used on its own or as an auxiliary lock. It is available in various models, for example: key both sides, key one side or key outside with thumb turn inside. The use of double cylinder functions on egress doors in any public building is prohibited by the National Building Code of Canada (1995), articles 3.4.- 7.12(14), A-220.127.116.11(14) and 18.104.22.168. Although use
of this type of lock function in a private residence is not regulated by the code, the Fire Marshall\’s Office will not support the use of any lock that could prevent the rapid departure of persons inside the building in emergency situations. Check local regulations.
Rim locks are face-mounted door locks. The lock body is mounted on the inside of the door and the strike is mounted on the inside of the frame. Latches or pins may be used in the rim lock. These locks are easily installed. However, the security afforded by a rim lock depends to a large extent on the method of fixing the lock and strike to the door and frame.
Mortise locks are designed to be installed in a mortise rather than being applied to a door\’s surface. They are usually used with solid-core doors or hollow metal doors.
C. Glass Door Locks
Glass doors with narrow stile frames require a lock with a pivoting bolt that moves deeply into the frame or stile of the inactive door. Where extra protection against prying is desired in a
sliding door, a hook bolt should be installed. Bolts should be made of hardened material designed to resist sawing attacks.
D. Cylinders and Keys
The cylinder, which receives the key, is the heart of the lock. The cylinder determines the size and shape of the key. A cylinder which screws into the lock body should have either a sloping edge or a rotating safety collar to resist removal with a vice wrench. A standard cylinder can be replaced by a high security cylinder to make the lock more resistant to picking, drilling and sawing attacks. A further advantage of this type of cylinder is the relative difficulty of acquiring duplicate keys.
Strikes are used to protect the lock bolt and to add strength to the total locking mechanism.