Entry Knob Lock
This is a standard cylindrical entry lock. It is locked and unlocked by a button on the inside, and key operated from the outside. When locked, some locks are inoperable from the inside until the button is turned or released. Others, referred to as “panic-proof,” allow free egress without operating the button. The lock may or may not unlock from the outside when the interior knob is operated. “Vandal-proof” locks allow the exterior knob to be turned when locked, without withdrawing the latch.
Entry Lever Lock
Lever locks are basically the same as knobs. However, they require much heavier duty return springs to prevent the levers from sagging over time. “Vandal-proof” designs are much more important with levers, as it is easier to apply force to a lever than a knob.
Storeroom Function Locks
Storeroom function knob and lever locks look just like entry locks. However, there is no button on the inside. Egress is always free, the exterior is always locked, requiring the use of a key to operate the lock every time. Mainly used for secondary entrances and secure areas, where you never want to leave the door unlocked. Some entry locks are designed to allow operation like a storeroom lock when the interior locking button is depressed AND rotated.
Mortise locks are box-like units mounted through the edge of the door, unlike the cylindrical locks shown above, which are mounted through circular holes drilled through the door. The mortise design is much older than the cylindrical, but can still be found in older homes. Modern mortise locks are more often found in commercial applications and some security gates. They are considerably more expensive than cylindrical locks. Modifications are required to switch from mortise to cylindrical locks or vice versa.
The deadlatch is a latch designed with an additional deadlatch plunger that can be seen here extended along the flat side of the latch. The deadlatch has a specific security function that requires proper installation and alignment with the strike plate. Properly installed, the latch should fall into the strike opening when the door is closed, but the deadlatch plunger should not. When held in the depressed position by the strike plate, the deadlatch plunger prevents the bypass of the latch by locking the latch in the extended position.
Springlatches should never be used with a keyed lock. This type of latch is easily bypassed with a credit card or other type of shim material or tool.
Deadbolt locks are far greater security than any other entry lock. Proper installation is critical to ensure that the bolt extends freely and fully. The bolt does not actually lock in place unless fully extended. Deadbolts may be single or double-sided, meaning they are key operated from only one side or both. We never recommend double-sided deadbolts because of the life safety risks they pose.
This is a standard pin tumbler lock cylinder. It can be rekeyed and/or masterkeyed. They come in a variety of keyways, which determines the type of key blank used to operate the lock.
Some locks are designed to use interchangeable cores. They are more commonly used in commercial applications. They are usually masterkeyed. Aside from the master key and individual operating key (also known as the change key), these locks have a control, or core, key that is used to install and remove the core from the lock. Hang on to that control key – it is needed to service the lock
Profile cylinders are more commonly used in Europe, but are increasingly found in the United States. They are most often found in storm and patio door locks. They may be keyed on one or both sides.
Above courtesy of Altic Lock.