Terminology Lock terminology used to describe High Security & Safety products AUTOMATIC DEADLOCKING - A device fitted to a lock where closing the door or gate reverts the bolt into a deadlocked state. BOLT - A device usually made from brass or steel used to secure a door or gate to its frame. DEADBOLT - A bolt which is put into the locked and unlocked position by the key only. The exception to this is a fire escape lock which can be unlocked from the inside, usually using a handle. DEADLOCK - A lock which is locked and unlocked by the key only. The exception to this is a fire escape lock which can be unlocked from the inside, usually using a handle. DETAINER - A unique, alternative to a lever which offers a greater number of key variations, particularly when the key is master keyed. DIFFERS - The number of different key combinations that are possible with a particular locking mechanism. DUAL CONTROL - A lock which can be locked/unlocked both electronically & mechanically. ESCUTCHEON - A protective plate around a key hole. Larger escutcheons support the key as it enters the lock ensuring correct alignment with the mechanism. FACE PLATE - Plate or outer forend which is the only part of a fitted mortice lock that is visible. HOOK BOLT - A lock with a hook shaped bolt used for securing sliding doors. HORIZONTAL - Lock which has its key hole and handle on the same horizontal line. LATCH - A bolt which is with drawn by the handle, not the key. LEVER - A moving obstruction in a lock activated by the key. Use of the wrong key will either over-lift or under-lift the lever rendering the lock inoperable. The more levers there are the greater number of key combinations. LOCKING LATCH - A latch which can be locked and withdrawn by the key as well as being withdraw by the handle when in the unlocked condition. LOCKS TO PASS - Any number of locks made to one key combination. MASTER KEYING - An arrangement which allows one key to operate a number of differing locks. MORTICE - Fixed into the edge rather than onto the face of the door. REVERSIBLE LATCH - A latch which can be reversed to suit opening in or opening out situation. SURFACE MOUNTED - Fixed onto the face of a door. SINGLE SIDED - A lock operable from one side only. (Such locks are handed) SUITED LOCK - A lock which is one of a number which are made to be operated by more than one key combination i.e. Master, Servant. THROW - The distance a bolt travels from the unlocked to the locked position. Some locks may have the bolt 'Double Thrown' by an extra turn of the key or a second key called the 'Doubles Key'. VERTICAL - Lock which has its key hole and handle on the same vertical line.