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Security Glossary of Terms

Your A to Z of Security Terms and Terminolog

Please click on a letter above to find the term you are looking for.

Abrasive Hard granular material of varying particle size, used in grinding and/or polishing, or incorporated in non-slip surface coatings.

Active Leaf First opening leaf of a pair of doors and usually houses the lock or latch.

Addendum Changes made to the specification.

Active Door (in a pair of doors) The leaf that opens first and the one to which the lock is applied.

Alcove A recessed space connected with or at the side ot a large room.

Alloy The combination of two or more metal elements to achieve special strength, hardness, corrosion resistance or appearance characteristics.

Anneal To heat metal, glass or other materials above the critical or recrystallisation temperature, then cool it to eliminate the effects of colour working, relieve internal stresses or improve electrical, magnetic or other properties.

Anodic Coating The surface finish resulting from anodising. See anodise.

Anodise To provide a non-corrosive oxide film on the surface of a metal, particularly aluminium, by electrochemical action. Anodising is available in varying colours, as well as natural, for decorative purposes.

Anti-Friction Bearing A bearing used in a hinge for the purpose of reducing friction and improving efficiency. Normally balls, oil-impregnated or other anti-friction material is used.

Anti-Friction Latchbolt A latchbolt equipped with a device for reducing friction between the bolt and strike. Usually a small trigger attached to the bolt contacts the strike and exerts a lever action to depress the bolt. Generally incorporated in longer throw latchbolts.

Approved Schedule A schedule reviewed by the architect and stamped as approved.

Arch A curved structure that carries the weight over an opening.

Architect A person who plans buildings and oversees their construction.

Architectural Hardware A part of the decorative and functional treatment of the building, its rooms and its door openings.

Astragal A member or combination of members applied to one or both doors of a pair at their meeting edges. The astragal closes the clearance gap for the purpose of either providing a weather seal, minimising the passage of light between the doors or retarding the passage of smoke or flame during a fire.

Attack Protection Components incorporated in locks and/or lock cylinders which are designed to increase security against manipulation by picking, raking or drilling.

Automatic Deadlatch See Deadlatch.

Authorised Key Cutter A business or person authorised by the lock manufacturer or agent to cut or bit that manufacturer’s or agent’s restricted keys.

Auxiliary Bolt An additional bolt which is activated by the strike when the door is closed automatically deadlatching the latchbolt against end pressure.

Auxiliary Lock A lock having a latchbolt or a deadbolt operated by a key or a turnsnib, or both. This type of lock is often used in addition to another lock, which may or may not be key operated, but which has a latchbolt operated by knobs or levers.

Auxiliary Spring A device or an accessory containing a hub and a spring to prevent the sagging of lever handles.

Backcheck An optional feature in hydraulic door closers, which takes effect at a certain degree of opening and controls the speed of the door during the balance of its opening cycle.

Backset The horizontal distance from the face of the lock to the centre line of the cylinder, key hole or knob hub.

Ball-Bearing Hinge See Hinge.

Barrel Key A key with a round shank and wing bit. The shank has a hole in the end, which is inserted in the lock. Used chiefly for cabinet locks.

Barrel a) A tubular portion of the cylinder which rotates when the correct key is used.
b) That portion of a hinge that is enlarged to receive the pin and act as the pivot point. It includes one or more knuckles from each individual leaf

Basement The lowest story of a building, partially or entirely below ground.

Batten A strip of board for use in fastening other boards together.

Beam A horizontal structural member that carries a load.

Bearing Partition A partition supporting any vertical load in addition to its own weight.

Benchmark A reference point used by surveyors to establish lines and grades.

Bevel Angle of the striking face of a latchbolt.

Bevelled Faceplate A faceplate shaped to fit the closing edge of a door which is not at 90 degrees to the face of the door.

Bitted Key Generally means a cut key. In lever locks, it means a key with the blade projecting at right angles from the shank.

Bitting A number that represents a depth of a cut on a pin tumbler-type key. A bitting is often expressed as a series ofnumbers and/or letters that designate all the cuts on a key.

Bolt The part of the lock or latch that projects to engage the strike or staple.

Bolt Projection The projection of a bolt frocrnthe faceplate when fully extended.

Bolt Throw The distance the bolt travels when it is extended.

Box Strike A strike in which the bolt recess is enclosed or boxed, thus covering the opening in the jamb.

Bright Finish A term used to describe builders’ hardware that is polished and buffed.

Broach The aperture into which the key is inserted.

Broad Butt Hinge A wider version of the butt hinge.

Budget Lock A lock usually operated by a square shape key, offering very little security.

Buffing The process of providing a lustrous finish by means of power-operated soft fabric wheels coated with a wax compound containing fine, abrasive particles.

Burnishing The process of developing a smooth, lustrous surface on metal parts by tumbling in a drum with small steel balls or by rubbing with hard metal pads.

Butt Hinge (or Butt) See Hinge.

Butt Weld A weld of members butting against each other.

Button-in-Knob An inside knob with a built-in button that controls the locking and unlocking of the outside knob. May be either push button or turn button.

Cabinet Locks Locks used in a variety of applications such as school lockers, store display cases, panels, desk drawers, showcases, letter boxes, sliding doors, wardrobe doors, file cabinets, chests, luggage and trunks, metal boxes cupboards and others.

Caulking A waterproof material used to seal cracks.

Cam A lever attached to the end of a barrel to activate the lock mechanism.

Cam Lock A cylinder assembly where the cam acts as a lock bolt.

Cap (of a lock) The removable lid of the case. Also called a cover plate.

Carbon Steel An alloy of iron and carbon, with varying small proportions of other materials such as manganese, silicon and copper.

Case Harden To produce a hard surface layer on steel by a process of heating, then rapidly cooling the metal in oil.

Case (of a lock) The housing containing the mechanism.

Casement A window whose frame is hinged at the side.

Casing The framing around a door or window.

Cavity Wall A masonry wall having an internal air space.

Centre Pivot A special type of hanging device for heavy-duty doors that usually swing both ways (double acting).

Centre-to-Centre Measurement from the centre of one member to the centre of another.

Change Key See Servant Key.

Channel A standard form of structural rolled steel, consisting of three sides at right angles in channel form.

Circuit The path for an electric current.

Classroom Lock a) Outside – opened by knob or lever except when knob or lever is made inoperative by keyfrom outside. The key locks or unlocks the outside knob or lever. b) Inside – opened by knob or lever at all times.

Clearance A space intentionally provided between building parts, either to facilitate operation or installation, to ensure proper separation, to accommodate dimensional variations or for other reasons.

Clutching A lock mechanism which allows the outside knob or lever to rotate free when locked. Unlocking then allows the knob or lever to withdraw the lockbolt to open the door.

Cold Rolled A term applied to metal sheet or plate that has been brought to final thickness and finish being passed, unheated, between heavy rollers.

Column A vertical supporting member.

Combination Locking Latch A lock with various latching functions operated generally by knobs or levers both sides except when locked by key outside or by key or turnknob inside.

Compressive Strength The property of a material that confers resistance to a crushing force.

Concealed Hinge See Hinge.

Condensation Water formed by warm, moist air contacting a cold surface.

Conduit A pipe or trough that carries electrical wiring, cables and other services.

Connecting Bar A bar connecting a barrel or turnknob to a lock mechanism.

Construction Keying Systems used to allow contractors to gain entry to a building during construction but to prevent entry by the same contractors after the building has been occupied or handed over.

Continuous Hinge See Hinge.

Control Key A key used to remove the removable core from a removable core cylinder or lock.

Coordinator A device used on a pair of doors to ensure that the inactive leaf closes first, before the active leaf. Necessary when an overlapping astragal is present, with certain exit device combinations and when automatic or self-latching bolts are used. Both door leaves must have closers.

Coping A masonry cap on top of a wail to protect it from water penetration.

Core Centre, inside

Corner Bracket (Door Closer Bracket) A bracket that is connected to a door frame jamb and head at the upper hinge corner, to support an exposed overhead door closer.

Corrosion The deterioration of metal by chemical or electrochemical action resulting from exposure
to weather, moisture, chemicals or other agents. A form of oxidation.

Court / Courtyard An open space surrounded partly or entirely by a building.

Crawl Space The space between the floor joists and the surface below when there is no basement. This allows access to make repairs on plumbing and other utilities.

Cremone Bolt A device, of surface application that by a turn of knob or lever handle, locks the door or the sash into the frame at top and bottom.

Curtain A security device used in lever locks to partially close the keyhole when the key or any other implement is inserted and turned.

Curved-Lip Strike A strike with a lip curved to conform to the detail of the door architrave.

Cut An indentation or notch made in a key that enables it to turn. It may be either square or rounded. In tumbler locks, the cuts align the tumblers properly to allow the key to rotate. In warded locks the cuts clear the wards and allow the key to rotate.

Cylinder The assembly incorporating the key-operated mechanism.

Cylinder Core See Barrel.

Cylinder Lock A lock having a mechanism operated by a cylinder.

Cylinder Ring See Escutcheon.

Cylinder Rose See Escutcheon.

Cylindrical Locksets Locks with a cylindrical housing which have a separate latchbolt.

Dead bolt A bolt which is not actuated by a spring. When locked the bolt cannot be returned by end pressure.

Dead latch A lock containing a deadlatch bolt.

Deadlatch Bolt A spring-actuated bevelled latchbolt which operates in conjunction with an auxiliary boltwhich automatically locks the latchbolt against return by end pressure.

Deadlock A lock incorporating a deadbolt.

Deadlocking Latchbolt A latchbolt which, when the door is closed, can be locked against return by end pressure by operation of a key or turnknob.NOTE: The door cannot be closed after locking the latchbolt therefore this type of lock is not acceptable for fire door sets.

Deadlocking Latch A lock incorporating a deadlockinglatchbolt.

Detainer See Tumbler.

Differs The variation between locks of similar design which allow each lock to be operated only by its own key. ie – keyed to differ

Direct Key Coding A code marked on a key or lock which, with no reference to another series of codes, discloses the key cuts for creating a workable key.

Disc See Tumbler.

Dogging Device See Holdback.

Door Closer (or Door Check) A device attached at the top or bottom of the door, either on the surface or morticed, to regulate and control the operation of the door.

Door Furniture Knobs, levers, handles, roses, plates or escutcheons used in conjunction with locks and latches.

Door Hardware A broad term used to group all the items that are fitted or related to doors, i.e., hinges, locks, padlocks, door closers, pull handles, bolts, stops, tracks, etc.

Door Holder Used for fastening a door in selected open positions.

Door Pull A handle or grip, commonly mounted on a plate, designed for attachment to a door to facilitate opening and closing.

Door Stop A device to limit the opening swing of a door. Also that part of a door frame against which the door closes.

Double Acting Door A door equipped with hardware that permits it to swing to either side of the plane of its frame.

Double-Acting Spring Hinge See Hinge.

Double Bitted Key One having bittings, or cuts, on two sides, to actuate the tumblers of the lock.

Double Egress A pair of doors that are comprised of two single-acting doors swinging in opposite directions, both doors being of the same hand.

Double-Hung Window A window having top and bottom sashes, each capable of movement up and down in its own grooves.

Double Rebate Frame A door frame having two rebates.

Double Throw Bolt A lock bolt that can be extended in stages to increase the bolt projection.

Drawing The process of pulling metal in solid form through dies to after its finish, mechanical properties or cross-sectional shape.

Drip A moulding designed to prevent rainwater from running down the face of a wall, or to protect the bottom of a door or window from leakage.

Drivers The upper pins in a pin tumbler cylinder.

Dry Wall a) A wall finished with wallboard in place of wet plaster or render b) A stone wall built without mortar.

Duct A sheet-metal tube used for air distribution.

Ductile A term used to describe metals soft enough to be stretched, drawn or hammered without breaking.

Dummy Cylinder A cylinder without an operating mechanism, for use where effect is desired.

Dummy Trim A non-operating door trim which is installed for appearance or as a pull handle only.

Eave The lower portion of a roof that extends beyond the wall.

Edge Plate An angle or channel-shaped guard used to protect the edge of a door.

Extension Link A device that can be linked to a cylindrical lock to increase the backset.

Extrusion a) The process of producing metal shapes by forcing heated metal through an orifice in a die, by means of a pressure ram. b) Any item made by this process.

Electric Strike An electrical device that replaces a regular lock strike to enable a door to be released by remote control.

Electrogalvanising The coating of ferrous metal with zinc by electroplating.

Electroplating The coating of a base metal object by the action of an electric current passing through the object submerged in a solution of a metal salt.

Elevation An orthographic projection of the vertical side of a building.

Emboss To produce a raised and/or indented pattern impression on a surface by means of patterned rolls or stamping dies.

Emergency Key A key supplied with Hotel/Motel locksets. These locksets have a feature which, when applied, prevents entry by normal service keys, master keys or grand master keys. At all times entry can be gained by the emergency key which suits those groups of locks.

Entrance Set A lockset with knobs or levers on both sides.

Escutcheon A plate, either protective or ornamental, containing openings for any or all of the controlling members of the lock such as knob, lever, handle, cylinder, keyhole, etc.

Etch To produce a textured finish on metal or glass by the corrosive action of an acid or other etchant.

Exit Device A door locking device designed to allow instant exit from an area, by pressing on a crossbar, which releases the locking bolt or latch.

Extension Bolt A flush bolt that has been lengthened to place the operating lever within reach of most people.

Facade The front or face of a building.

Faceplate A front plate through which the bolt projects.

Facing Any material forming a part of a wall used as a finished surface.

Fatigue Structural failure of a material caused by repeated application of stresses.

Ferrous A term applied to materials containing iron.

Ferrous Metal A metal containing or derived from iron.

Fibreboard Sheet material of refined wood fibres.

Fibreglass a) A material composed of thin glass threads used for insulation. b) Glass fibres bonded with resin that can be used to manufacture a range of objects.

Filigree Fine, decorative metal openwork usually diecast and used to decorate reproduction push plates and door furniture.

Fireproofing Any material protecting a building’s structural members that increases their fire resistance.

Fire Wall A wall extending from a building’s foundation through to the root which subdivides the building, in order to restrict the spread of fire.

Fixed Pin Butt See Hinge.

Flashing The sheet metal work used to prevent leakage aver windows and doors, around chimneys, and at the intersection of different wall surfaces and roof planes.

Flat Key A thin, flat, stamped key, usually steel and usually having square-cut bitting on one or both sides.

Flat Key Locker Lock Used to lock metal storage lockers in factories, schools or similar facilities.

Flat Lip Strike A strike with a flat (non-curved) lip.

Floor Closer A door closing device that is installed in a recess in the floor below the door in order to regulate and control the opening and closing of the door.

Floor Plan An orthographic projection of the floor of a building.

Flush Bolt A door bolt so designed that when installed, it is flush with the face or edge of the door.

Follower See Hub.

Foot Bolt A bolt designed for attachment to the bottom of a door. Usually the bolt is controlled by a trigger, which holds the bolt against a spring. Release of the trigger permits the spring to move the bolt into the unlocked position.

Fore-end See Faceplate.

Forging Shaping metal by impact or pressure. The metal may be heated prior to shaping.

Framing Timber used for the structural framing of a building.

French Door A door with glass panes throughout its length, usually with narrow stiles.

Furring Wood strips fastened to a wall or ceiling for the purpose of attaching wallboards or ceiling tiles.

Gable The triangular portion of an end wail formed by a sloping roof

Galvanising The process of coating metal with zinc, either by dipping in a bath of molten zinc or by electrolytic action.

Gating The opening in lever tumblers which permits actuation of the bolt.

Gauge A number indicating the thickness of materials.

Grand Master Key (GMK) A key within a master key system that operates all locks in a number of separate groups which have their own master key.

Great Grand Master Key (GGMK) The same as GMK but usually consists of more than one GMK group. These are then controlled by one GGMK key.

Guest Key A hotel/motel room key that is lent to the guest, usually keyed to differ under a master key group.

Grout Mortar of pouring consistency.

Gutter A trough or depression for carrying off water.

Gypsum Board Lining Board made of plaster with a covering of paper (also called “plasterboard”).

Hand The direction of door travel (swing or sliding) and the locking/security side of a door, i.e., a righthand or right hand (opening out), Iefthand or left hand (opening out).

Handed A product designed or assembled for use only on right hand doors, or only on left hand doors, but not both.

Hardboard Sheet material of compressed fibres.

Hardness The measure of the resistance of a material to indentation, wear or abrasion.

Hardware Set A group of hardware listed in the specification, for a specific opening.

Hardwood Wood from trees having broad leaves in contrast to needles. The term does not necessarily refer to the hardness of the wood.

Headroom The vertical clearance in a room or on a stairway.

Hinge Two jointed plates hinged together and attached to a door and its frame. Serves to support or “hang” the door and allows the door to swing or move. Hinges are classified according to installation method.

a) Full Mortice A hinge with one leaf morticed in the edge of the door, the other leaf morticed in the door jamb.

b) Non-Mortice A hinge which has both leaves, surface fixed onto the door and the jamb.


Hinge Types


Ball-Bearing Hinge A hinge equipped with ball bearings between the hinge knuckles to reduce friction.
Butt Hinge (or Butt) A hinge morticed into both the door and frame.
3) Concealed Hinge A hinge so constructed that no parts of the hinge are exposed when the door is closed.

Continuous Hinge A hinge designed to extend for the length of the moving part to which it is applied. Also called a “piano hinge“.

5) Double-Acting Spring Hinge A device for hanging a door, permitting the door to swing in either direction and return to a closed position.

6) Fixed Pin Butt A hinge in which the pin is fastened permanently in place, preventing separation of the two leaves.

7) Lift Off Hinge A hinge having only two knuckles, to one of which the pin is fastened permanently, the other containing the pinhole, whereby the two parts of the hinge can easily be separated. These hinges are handed.

8) Loose Pin Hinge A hinge having a removable pin to permit the two leaves of the hinge to be separated.

9) Olive Knuckle Hinge A hinge with an oval-shaped single knuckle.

10) Paumelle Hinge A style of hinge using a single, pivot-type knuckle. Generally modern, or streamlined design.

11) Plain-Bearing A standard hinge without ball, oil-impregnated or anti-friction bearings.

12) Shutter Hinge A hinge designed to swing shutters.

13) Spring Hinge A hinge containing one or more springs to move the door into a closed position. It may be either single or double-acting.

14) Strap Hinge A surface hinge of which both leaves are of considerable length.

15) Surface Hinge A hinge having both leaves secured to the surface of the door and frame.

16) T-Hinge A surface hinge with the short member attached to the jamb and the long member attached to the door.


Hinge Backset Distance from back end of a hinge to edge of the inside door surface

Hinge Jamb Vertical member of a door frame to which the hinges are applied.

Hinge Stile (of a door) The door stile to which the hinges are applied.

Hip Roof A roof with four sloping sides.

Holdback A snib, button or other device which can hold the bolt in the retracted position.

Hook Bolt A lock bolt that hooks onto the strike usually applied to sliding doors.

Hot Rolled Shaping a heated form of metal between rollers.

Hot Working. The process of forming a metal at extremely high temperature.

Hotel Motel Lock A deadlatching locket function developed for hotels and motels to provide a privacy lockout feature to protect the property and privacy of guests. When necessary management may also apply the lockout using an emergency key from outside.

Hub Part of the lock which connects the furniture spindle to the lock mechanism. –

Inactive Leaf Second opening leaf of a pair of doors. It usually houses the strike.

Indicator A device that shows the state of the locking mechanism, locked or unlocked. Used for toilet cubicles, etc

Indirect Key Coding A code marked on a key or lock which requires reference to another series of codes to disclose the key cuts for creating a workable key.

Individually Keyed See Keyed To Differ.

Inset The distance from the face of the door to the face of the jamb.

Insulation Material for obstructing passage of sound or heat from one surface to another.

Interchangeable Core System A cylinder which can be removed from its lock by a special control key.

Interlocking Joint A joint formed between sheet metal parts by engaging their edges, which have been pre-formed to provide a continuous splice.

Ironmongery See Door Hardware.

Jalousie A type of window consisting of a number of long, thin, hinged panels.

Jamb The vertical member forming the side of a door, window or wall opening frame. The hinge jamb is the jamb at which the hinges or pivots are installed. The strike jamb is the jamb in which a strike may be installed and away from which the door or window swings. A blank jamb is one that has not been prepared to receive hardware.

Jamb Depth The width of a jamb, measured perpendicular to the door or wall face at the edge of the opening.

Keeper See Strike.

Key The device which activates the lock mechanism or cylinder.

Key Bit Generally a cut in a key. In lever locks, it means the projecting part of a key which allows it to activate the locking mechanism

Key Blank An uncut key.

Key Changes The number of differs available under a given system.

Key Code A record of key bitting.

Key Hole Lock A small lock mechanism designed to block the keyhole of a lever lock.

Key In Knob (or lever) Various locking and latching functions operated by a knob or lever complete with a cylinder or turnknob, incorporated within the knob or lever.

Key Latching Indicates the operation of the key – withdraws the bolt.

Key Locking Indicates that operation of the key lock or unlock the furniture and/or the bolt of the lock.

Key Plate See Escutcheon.

Key Profile The shape of the cross-section of the key which matches the broach.

Keyed Alike Indicates identical keying for two or more locks.

Keyed To Differ A different key is needed to activate each lock.

Keying Schedule A complete listing and explanation of all keys and keying requirements.

Keyway See Broach.

Kick Plate A protective plate applied on the lower rail of a door to protect against the door being damaged.

Knob A projecting part, usually rounded, forming the handle for a lock.

Knob Shank The projecting stem of a knob into which the spindle is fastened.

Knuckle The enlarged part of a hinge into which the pin is inserted.

Labelled Door (or Frame) A door or frame that conforms to all the applicable requirements, in respect to fire resistance, of a nationally recognized testing authority and bears a label designating that fire rating.

Laminate The process of or a product made by, bonding together two or more layers of material or materials.

Landing A stair platform.

Latch A door fastening device having no locking function.

Latchbolt A spring-actuated, bevelled bolt usually operated by door furniture.

Latchset A door fastening mechanism, comprising of latch, strike and door furniture.

Lateral Movement Movement toward the side, sideways.

Lead-Lining The lining of a door, frame or lock with sheet lead. Primarily used in hospitals or other areas where there is a potential radiation hazard. May also be used for soundproofing.

Leaf a) Hinge – One of the two movable plates which, when fastened together by the hinge pin, form a complete hinge. b) Of a pair of doors – one of the two doors forming a pair of a double door.

Legal Measures Patent protection or design registration.

Lever See Tumbler.

Lever Handle A bar for operating the latchbolt of a lock.

Lever Lock A lock operated by a lever mechanism.

Lift Off Hinge See Hinge.

Lip of Strike The projecting part of the strike on which the latchbolt rides. It may be either a curved lip or flat lip.

Lock A fastening device activated by a key and/or turnknob and/or electricity

Lock Rail (of a door) The horizontal member of a door that houses the locking mechanism.

Lockset A lock, complete with strike and door furniture, such as knobs, levers, escutcheons, or handles.

Lock Stile (of a door) The vertical member of a door in which the lock is housed, as distinguished from the hinge stile.

Loose Pin Hinge See Hinge.

Louvre A ventilating window covered by sloping slats to exclude rain or light.

Lubricity The property of slipperiness, oiliness, smoothness.

Magnetic Catch A cupboard catch that uses a magnetised strike to hold the door closed.

Malleable A term used to describe metals that can be hammered, pounded or pressed into various shapes.

Maison Key System A keying system where a group of different keys will operate a common lock.

Master Key A key which will operate a group of locks, where each lock is generally keyed to differ.

Master Key System A system where locks are passed by two levels of keys. The lower level of key (keyed to differ) fits only that lock or those locks keyed alike. The higher level (master key) fits all locks in the system.

Meeting Stile The vertical edge of a door or window, in a pair, which is adjacent to the other door or window.

Metallurgy The science or technology of metals.

Mortice An opening, recess or cutout made to receive a lock or other hardware. Also the act of making such an opening.

Mortice Lock A lock designed to be inserted into the edge of a door, rather than being mounted to its surface.

Mould A form into which molten metal is poured to produce a casting.

Moulding Strips used for ornamentation.

Mullion A fixed or movable vertical member dividing a door opening.

Muntin The small members that divide the glass in a window frame.

Mushroom Pins A mushroom shaped pin used in a pin tumbler mechanism to increase pick resistance.

Niche A small recess in a wall.

Nightlatch A rim or mortice lock, with a spring-actuated latchbolt, operated by key or turnknob.

Non-Ferrous Metals that do not contain iron.

Nosing The rounded edge of a stair tread.

Offset Pivot A special hanging device for heavy-duty doors, used on doors swinging one way only.

Olive Knuckle Hinge See Hinge.

Opening Size The size of a door frame opening, measured horizontally between jamb rebates and vertically between the head rebate and the finished floor. The opening size is usually the nominal size and is equal to the actual door size plus clearances.

Organic Coating A coating such as paint, lacquer, enamel or film in which the principal ingredients are derived from animal or vegetable matter or from some compound of carbon.

Overhang The horizontal distance that a roof projects beyond awafl.

Oxidation The reaction of substances with oxygen (air). This characteristic is both beneficial and detrimental in Architectural Hardware. Rust and corrosion are detrimental, destructive forms of oxidation. On the other hand, a finish that darkens with use, i.e., oxidised bronze or copper’s “patina” are examples of attractive, essentially non-destructive forms of oxidation.

Padbolt A sliding bolt lockable by a padlock.

Padlock A small, portable lock consisting of a case containing a lock mechanism, a shackle or U-shaped bar that fastens into the lock case, and usually a key to open the locking mechanism.

Panel A flat wood, metal or glass surface framed in either wood or metal.

Panic Hardware See Exit Device.

Parapet The portion of a wall extended above the roof.

Particleboard A board of bonded wood chips.

Partition An interior wall, normally non load bearing.

Passage Set A latchset with knobs or levers on both sides of a door but no locking function.

Patina A film on bronze or copper formed by oxidation verdigris.

Patio Lock A lock designed with a push button or turnbutton inside to lock the outside knob or lever. When locked, there is no entrance from outside.

Paumelle Hinge See Hinge.

Physical Properties Those properties of a material such as specific gravity or density, electrical and thermal conductivities, and co-efficient of thermal expansion, which serve to characterise and distinguish between different materials.

Piano Hinge See Hinge (Continuous Hinge).

Picking Manipulation of the tumblers or bypassing the wards in a lock mechanism, without a key, permitting the mechanism to be unlocked

Pickling he treatment of metal surfaces with a strong oxidising agent such as nitric acid, to make them chemically clean and provide a strong, inert oxide film.

Pin Tumbler See Tumbler.

Pitch A term applied to the amount of a roof slope.

Pitting Localised surface defects on metals, in the form of small depressions, or “pits”

Plain-Bearing Hinge See Hinge.

Plug See Barrel.

Plumb Vertical.

Plywood Wood made up of three or more layers of veneer bonded with glue.

Privacy Set A lock used on bathroom and bedroom doors having an inside button or turnknob to lock the knob or lever and usually an emergency function which will unlock the set from the outside.

Project Keying See Construction Keying.

Pull Handle A grip applied directly to the surface of the door or a fixed handle applied on a plate used as a means of pulling a door open.

Punching The process of forcing a punch through metal into a die, forming an opening.

Push Key A key which performs its full functions by inward rather than rotary motion.

Push Plate A plate placed on the surface of a door to protect it from wear and soiling, as a result of persons pushing the door open.

Quenching The process of cooling heated metal by contact with a liquid, gas or solid, for purposes of hardening or tempering.

Rafter A member in a roof framework running from the eave to the ridge. Types of rafters are hip rafters, jack rafters and valley rafters.

Rail A full-thickness, horizontal structural member forming the top or bottom edge of a door or sash. May be located at an intermediate height in a door, separating panels or glazed areas.

Rebate A term used to define that portion of a door frame into which the door fits.

Rebated Door A door where the leading edge is stepped.

Rebated Lock / Latch A mortice lock or latch which has the faceplate and strike shaped to match the rebated edge of a door, usually the meeting edges of two door leaves.

Regular Bolt A latchbolt with the bevel set to suit a door opening in.

Removable Core Cylinder A cylinder containing an easily removable core assembly, which incorporates the entire tumbler mechanism including the barrel, tumblers and separate shell. The cores normally are removable and interchangeable by use of a special key (called a “control key”).

Removable Mullion A mullion separating doors vertically within a door frame. Required for the normal operation of doors but designed to permit its temporary removal so the entire width of the opening can be utilised.

Restricted Key A key which can only be obtained through an authorisation system.

Restricted Profiles Profiles and broaches that are generally used in special keying systems.

Return A moulding turned back to the wall on which it is located.

Reveal (of a door frame) a) That part of a back bend that projects out from the finished wall. b) The dimension from the inside face of a door, when in the closed position, to the face of the frame at the side opposite from the direction of the door swing.

Reverse Bolt A latchbolt with the bevel set to suit a door opening out.

Reversible Bolt A latchbott that can be adapted to suit doors of either hand, opening in or opening out.

Reversible Lock A lock with components that can be readily adapted to suit doors of either hand, opening in or out.

Rib A raised ridge or fold formed in sheet metal to provide stiffness.

Rim Lock, Rim Latch A lock or latch which is mounted to the surface of a door, rather than inserted into it.

Riser The vertical board of a step. It forms the front of the stair step.

Roller Bolt A spring-loaded, roller shaped bolt.

Roller Strike A strike incorporating a roller at the point of bolt contact to minimise friction.

Rose See Escutcheon.

Rotor See Barrel.

Sash A framing for windowpanes. A sash window is generally understood to be a double-hung, vertically sliding window.

Satin Finish Architectural or builders’ hardware that has been scoured with an abrasive to achieve a dull lustre.

Schedule A list of parts or components (such as a hardware schedule).

Scheduling The detailing of openings or doors, listing their locations and the door and frame materials, and the listing of hardware in detail and quantity

Scheduling Sequence A proper and orderly listing of various hardware items for each door.

Scouring The application of a fine abrasive to achieve a satin, or dull, finish. The abrasive may be applied by hand, wheel or belt.

Section An orthographic projection that has been cut apart to show interior features.

Servant Key The individual key to a lock in a master key system.

Service Key See Servant Key.

Services Key A servant key used to operate a number of locks, e.g., locks for fire services, buildings’ services or emergency services.

Sequence Closer A door closer that automatically closes a pair of fire rated doors in sequence so as to ensure correct latching.

Shank (of a knob) The projecting stem of a knob into which the spindle is fastened.

Shear Line The interface between the plug and shell in a cylinder that is normally obstructed by the pin tumblers. The pins must be raised to the shear line by the correct key to allow the plug/key to turn.

Short Backset Locks Locks suitable for narrow stile doors.

Shutter See Curtain.

Shutter Hinge See Hinge.

Side Bar Mechanism A method, additional to tumblers, of preventing the barrel from rotating in the cylinder housing.

Sidelight A narrow window adjacent to a door.

Silencer A small piece of resilient material attached to the stop on a door frame to cushion the closing of the door.

Sill The stone or wood member across the bottom of a door or window opening. Also the bottom member on which a building frame rests (sill plate).

Single-Acting Door A door mounted to swing to only one side of the plane of its frame.

Single-Action Escape Lockset A locket installed to a door where exit is obtained by a single action without the use of a key.

Single-Rebate Frame A door frame having only one rebate.

Sintering The solidification and fusing of compressed powdered metal.

Sliding Door Pull A pull that is either flush with the edge of the door or with the face of a sliding door.

Snib A device used to either hold back or lock the bolt.

Soffit The under surface of the stop at the frame head. That portion of a door frame between the rebates on a double-rebated frame or between the rebate and the outer edge of the frame on the stop side of a single-rebated frame. Sometimes referred to as the “stop width”.

Span The distance between structural supports (i.e., the length of a joist, rafter or other member).

Specification A written document that accompanies the working drawings, which sets forth standards for the materials used in the construction of buildings. It also covers all conditions relating to that construction or type of construction.

Spindle The drive shaft that connects the knob or lever to the latch or lock mechanism to operate the bolt.

Spinning A process for shaping sheet metal into rounded objects. During the process a tool is pressed against the sheet metal as it revolves.

Split Spindle A spindle consisting of two half-spindles which allow independent functions on each side of the lock.

Spool Pin A double ended mushroom pin.

Spraying The process of coating materials with paint or clear lacquer by use of air pressure or see cat.

Springbolt See Latchbolt.

Spring Hinge See Hinge.

Staple A surface-mounted strike.

Stator Intermediate sleeve between barrel and cylinder.

Stile The vertical members of a door to which the lock and hinges are applied.

Storeroom Locks a) Outside – opened by key, knob or lever is always rigid. b) Inside – opened by knob or lever at all times.

Strap Hinge See Hinge.

Strike A device fixed in or on a door jamb into which the lock or latch bolt engages when the door is closed.

Strike Box A component used in conjunction with the strike plate to help protect the bolt against end pressure.

Strike Lip The leading edge of a strike which is usually curved to engage the bevelled face of a latchbolt.

Stud The vertical member that forms the framework of a partition or wall and editor of this glossary.

Surface Bolt A rod or bolt mounted on the face of the inactive door of a pair to lock it to the frame

Tail Piece a) for locksmiths, the sliding part or connecting link through which the bolt is operated by hub or key, b) for manufacturers, see Connecting Bat-.

Takeoff The listing of openings and the appropriate hardware from a set of floor plans and door schedule.

Tempering The process of heating metal, glass or other material to a temperature below the transformation stage, then cooling it at a controlled rate to change its hardness, strength, toughness or other property.

Tensile Strength Resistance to a force tending to tear the material apart.

Terrazzo Floor covering of marble chips and cement ground to a smooth finish. Metal strips are used to separate different colours and create designs.

Thermal Stress Stress within a material caused by temperature variations.

T-Hinge See Hinge.

Threshold A strip fastened to the floor beneath a door. May be required .to cover the joint of two types of floor materials where they meet.

Throw See Bolt Throw.

Thumb Latch The small pivoted part above the grip of a handle intended to be pressed by the thumb to operate the latchbolt.

Thumb Turn See Turnknob.

Tongue See Bolt.

Translucent Having the ability to transmit light but not a clear image.

Transom A small window over a door.

Transom Closer A closer concealed in the frame header with an arm connecting to the door at the top rail.

Transparent Having the ability to transmit light without distortion so that clear images may be seen.

Tread T he horizontal part of a step.

Trim See Escutcheon.

Tubular Bolt A bolt having a tubular case.

Tubular Lock One having a tubular shaped case and requiring bored (round) holes rather than a chiselled rectangular mortice.

Tumbler A component of a lock or cylinder which prevents operation of the lock mechanism except by insertion of the correct key. Tumblers may take the form of pins, discs, levers, bars, wafers or detainers.

Turn Button See Turnknob.

Turn Piece See Turnknob.

Turnknob A device used to lock, unlock or retract the bolt.

Turnsnib See Turnknob.

Unit Lock A lockset constructed so that its mechanism, knobs, levers, and escutcheons form a permanent complete assembly.

Universal Strike A strike plate which is common to most tubular, cylindrical and mortice locks.

Utility Lock Also called “cam locks”. Used for a variety of locking purposes. They are identified by the flat metal piece extending from the lock barrel, which is the cam.

Wafer See Tumbler.

Wainscot An ornamental covering of walls, often consisting of wood panels, usually running only part way up the wall.

Wall An exterior wall (see partition).

Ward An obstruction projecting from a lever lock case or side of the key hole intended to block the entrance or rotation of an improperly cut key.

Warded Key One having grooves or notches designed to clear the warding of the lever lock.

Weatherstrip Narrow strip made of metal, or other material, designed so that when installed at doors or windows it will retard the passage of air, moisture or dust around the door or window sash.

Working Drawing A plan of a building, or part of a building, that shows the position of doors, windows and other features required to develop an Architectural Hardware schedule.