half moon cut
n. a semi-circular cut in the bolt throw bit of a key, with the cut axis running parallel to the key shaft. Found typically on a key for a high security lever safe lock.
half mortise
1. adj. pertaining to an installation prep that typically leaves the bolt face plate and a perpendicular surface of the lock visible, with visible surfaces being flush mounted, 2. v. to make a cavity in a door or drawer that is open on the edge and on one side of the door or drawer, 3. adj. pertaining to a locking device designed to fit in a half mortise prep
half-mortise hinge
n. a hinge which has one leaf mortised into the door and the second leaf applied to the surface of the frame
half-surface hinge
n. a hinge which has one leaf mounted onto a face of the door and the second leaf mortised into the frame
hand change
adj. pertaining to a combination lock in which the wheels must be removed in order to change the combination
adj. pertaining to hardware which is manufactured only for application on doors with a specific orientation
n. a complete lock or latch assembly which incorporates a pitcher handle
handicapped code
n. any building code designed to ease access for handicapped persons
hang (rake & hang)
v. to cause a top or master pin to rest on the plug when picking
hardened core (pin)
adj. a bottom or top pin which is bimetallic, the central portion of which being hardened metal intended to resist drill attack
n. a tempered barrier placed between the lock and the outside of a safe to inhibit drilling
hard wire system
n. a system which uses metallic conductors to connect the various sensors to the central processor
hardware key
n. a computer hardware component which protects copyrights by preventing software from running on any computer where the key is not installed. The key is typically accessed via one of the ports.
hardware schedule
n. a listing of the door hardware used on a particular job it includes the types of hardware, manufacturers, locations, finishes, and sizes. It should include a keying schedule specifying how each locking device is to be keyed.
n. a hinged metal strap designed to be passed over a staple and secured in place
n. the horizontal, top, member of a door jamb
heel & toe locking
n. describes a padlock which has locking dogs at both the heel and toe of the shackle
heel (of a padlock shackle)
n. the part of a padlock shackle which is retained in the case when in the unlocked position
height adjustment screw
n. a screw contained within the hinge block of a safe that raises or lowers the door to clear the frame
helmet lock
n. auxiliary lock on motorcycles used to secure a helmet
abb. horizontal group master key
abb. high coercivity
high coercivity
adj. a high energy form of magnetic encoding measuring in the range of 2400 to 4000 Oe which is resistant to accidental erasure
high security cylinder
n. a cylinder which offers a greater degree of resistance to any two or more of the following: picking, impressioning, key duplication, drilling or other forms of forcible entry
high security key
n. a key for a high security cylinder
hinge security stud
n. a protrusion on one leaf of a hinge which interlocks with the other when the door is closed
hinge stile
n. the vertical edge of a door where hinges are installed
hinged shackle
n. a shackle whose heel is permanently mounted to the padlock case in a manner which allows the shackle to pivot to open
abb. housekeeper's key
Hobbs shackle
n. a hinged shackle with a notch for the bolt in its movable end
hold open
n. 1. a function of self latching hardware which allows a lock to be set in a non-latching mode 2. A function of a door closer, or separate hardware device, which allows the door to be retained in an open position
hold open arm
n. a door closer arm with the capability of maintaining the door in the open position
hold open cylinder
n. a cylinder provided with a special cam which will hold a latch bolt in the retracted position when so set by the key
n. a function of some self latching locks which allows selective retention of the bolt to prevent latching when the door is closed
holding fixture
n. a device which holds cylinder plugs, cylinders, housings, and/or cores to facilitate the installation of tumblers, springs and/or spring covers
hole change (wheel)
n. a perforated tumbler that may have its combination set by placement of a fly relative to, or in, one of the perforations
hollow core door
n. a non-metal door with structural reinforcement creating air pockets between the two faces
hollow driver
n. a top pin hollowed out on one end to receive the spring, typically used in cylinders with extremely limited clearance in the pin chambers
hollow metal door
n. typically a door made of sheet metal on all surfaces and lightly reinforced to make it rigid
n. a vertical surface at the top of a cut angle that prevents smooth insertion or withdrawal of a key
hook bolt
n. a lock bolt shaped in the general outline of a hook. Normally used on sliding doors or where spreading of the frame and door is a possible attack.
hook pick
n. a pick with a tip that curves upward by 45 or more toward perpendicular to the blade
hook ward
n. a ward that has an offset requiring an 'L' shaped cut in the key
horizontal exit
n. an exit to the outside or an area of refuge on the same or nearly the same level
horizontal group master key
n. the two pin master key for all combinations listed in all blocks in a line across the page in the standard progression format
horizontal locking
n. the locking mechanism associated with vehicle doors with horizontal linkage
n. in a non-cylinder lock, the housing which surrounds the nose and extends through the door or drawer
horn plate
n. the cover of a lever tumbler lock case to which the horn is attached
hospital hinge
n. a hinge with a large chamfer at each end of the knuckle
hotel cylinder
n. a cylinder which can function to prevent the operation of all keys except emergency, display and some shut out keys. It may also contain an indicator.
housekeeper's key
n. a selective master key in a hotel master key system which may operate all guest and linen rooms and other housekeeping areas
n. that part of a locking device which is designed to hold a core
abb. hardplate
n. 1. a lock component, which redirects rotational motion from a spindle or shaft to linear movement of a latch or bolt, 2. (key change), the part of a combination wheel that the change key engages to permit the combination to be changed
hybrid key
n. a key that can operate locks using two or more different technologies in one device, e.g. mechanical/electronic, mechanical/magnetic, etc.
hybrid locking system
n. a locking system which derives its security from two or more different technologies operated by the same key in one device, e.g. mechanical/electronic, mechanical/magnetic, etc.


A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Appendix

This listing of the Locksmith Dictionary is courtesy of