To help you in your search for a hardware product, the following glossary provides an overview of frequently used construction industry abbreviations and their definitions. To search by abbreviation, select a letter from the list below.

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


Abbreviation Definition

A Ampheres or Amps
Ack Acknowledge
AE Authorized Entry
AH Allen Head (screws); usually followed by
A.H.C. Architectural Hardware Consultant
AL . Aluminum; also Alum
AMS All machine screws
AN Anodized
ASA American Standards Association
AU Auxiliary
AWG American wire gauge
AWS All wood screws
Top
 
BB Ball bearing
Bev Beveled (as in lock front, door edge or stile)
B.H.M.A. Builders Hardware Manufacturers Association
BPS Bolt position switch
BS Backset (of a lock)
BTB Back to back; also B to B
Top
 
C Center of centerline
C Common
CCTV Closed circuit television
CF Customer furnished
CFC Cut for cylinder; also used - C for cylinder; C/C and cut/cyl
CFT Cut for turn knob; also used - C/th, CFTT, c for t.k.
CH Channel
CI Channel iron (door frame)
CLS Closed loop secure
Corr Corridor
CS Concealed switch (hinge)
CTC Countersunk
Cyl Cylinder (of a lock)
Top
 
DA Double acting
DB Decibel
Dbl. Double; also used Dble
Deg Degree
Dia Diameter
DP Dust proof
DP Display panel
DPS Door position switch
DPS Dust proof strike
DPDT Double pole double throw
Dr Door
DT Dummy trim
Top
 
Ea Each
Eq Encl Equipment Enclosure
EOL End-of-line resistor
ES Expansion shield
Ext Exterior
Top
 
FBT Flat button tip (hinge)
FD Fire door
FH Flat head (screw)
Fl Floor
Fr (of a door or sash); commonly used with
FS Fail-safe operation
Top
 
Ga Gauge
Gal Gallon
GN Grommet nut
GND Ground
Top
 
HC Hollow core
Hdg Heading
HM Hollow metal
Hr. Hour (¾hr.,1½hr.,3hr-fire door ratings)
HT Hospital tip (hinge or pivot)
Hz. Hertz
Top
 
ID Inside diameter
Int. Interior
Int. Intermittent duty
Top
 
J Jamb
J Jack
Top
 
Kal. Kalamein; also K
Ka Keyed alike
KD Keyed different
KVA Thousand volt amp
Top
 
L Lip (of a strike)
LBR Less bottom rod (of a vertical rod type exit device)
L/C Less cylinder
L.E.D. Light emitting diode
LH Left hand
LHRB Left hand reverse bevel
LL Lead lining (of a door)
Lox. Locks
LP Light-proof (door)
LS Lead shield
LT Lamp test
Top
 
M Meter
M.A. Milliamps
Maint. Maintained
MC Metal clad
M x M Metal by metal; denotes metal door in metal frame
Max. Maximum
Min. Minimum
Mom. Momentary
MS Machine screws
Top
 
NS Narrow stile
Top
 
OB Oilite bearings (as in hinge)
OBS Open back strike
OD Outside diameter
OH Oval head (screw)
O.H. Overhead (door)
O.L.S. Open loop secure
OS Outside
OSKP Outside knob pinned
OST Outside trim; also OS/T
Top
 
P Plug
PBS Protected box strike; also used PBX
P.C. Printed circuit
PH Phillips head (screw)
P.L. Power lock
P.O.A. Price on application
Pr. Pair
P.S. Power supply
PSI Pounds per square inch
P.U.L. Power unlock
Top
 
Rab. Rabbeted
Rad. Radius
RB Reverse bevel
RC Rounded corners
RF Radius front; denotes lock or flush bolt with
Reg. Regular
Rem. Mul. Removable Mullion (for use with exit device)
RH Round head (screw)
RH Right hand
RHRB Right hand reverse bevel
Rm. Room
RA Remote alarm
RR Remote alarm
RR Remote reset
Rtn. Return
Top
 
Sgl. Single
SH Security safety stud
SH Spanner head (screw)
SMS Sheet metal screws
SNB Sex nuts and bolt; also SBN
Spdle. Spindle (for a knob)
S.P.D.T. Single pole double throw
SS Stainless steel
Std. Standard
STMS Strike to template machine screw
STS Self-tapping screw
Top
 
TB Terminal block
TB Through bolts
TBGN Through bolts and grommet nuts
TBN Through bolts and nuts
TC Tin clad
TD Time delay
TMS or tms To Template with machine screws
Top
 
UC Undercut (door)
UC Undercut head (screws); also used US and UCH
UL Underwriters Laboratories
US United States; commonly used as prefix to
Top
 
VA Volt amps
VAC Volts alternating current
VDC Volts direct current
VOM Volt-ohm meter
Top
 
Wd Wood
WD x MF Wood door x metal frame
WD x WF Wood door x wood frame
WS Wood screws
Top
 
x By (i.e. HMD x HMF)
X-bar Cross bar (of an exit device)
Top
 
Yds. Yards
Top