Acronyms and Abbreviations in Engineering

Acronym: An abbreviation formed from the initial letters of other words and pronounced as a word. example CAD.

Abbreviation: a shortened form of a word or phrase. Example: DIA for diameter.

Using too many acronyms or abbreviations can make a drawing harder to understand. I recommend shorted words only if you can’t fit the whole word on the drawing. This stop those pesky “what does this mean?” questions from site.

Below is a handy list of what that engineering acronym or abbreviation means.

Complied by Allan Wise, based in Australia

Created 7-July-2004
Revised 20-Nov-2004
Revised 20-Dec-2005
Revised 16-August-2006
Revised 30-April-2020
Revised 22-May-2020

A

A – Ampere

A/C – Air Conditioning

A/H – After Hours

AB – As Built

ABBR – Abbreviation

ABS – Absolute

ADD – Addendum

AEC – Architecture, Engineering, and Construction

AF – Across Flats

AFL – Above Floor Level

AFL – Above Finished Level

AG – Agricultural pipe drain

AGL – Above Ground Level

AHD – Australian Height Datum

AHU – Air Handler Unit

APPROX – Approximately or Approximate

ARRGT – Arrangement

AS – Australian Standard

ASCII – American Standard Code for Information Interchange

ASSD – Assumed Datum

ASSY – Assembly

ATF – Along Top Flange

AUTO – Automatic

AUX – Auxillary

AVG – Average

B

B – Basin or Bottom

BLDG – Building

BNS – Business Network Services

BOT – Bottom

BQ – Bendable Quality

BRG – Bearing

BRS – Brass

BSP – British Standard Pipe

BT – Bath Tub

BT – Boundary Trap

BTM – Bottom

BW – Both Ways

C

C – C shaped steel purlin

C/C – Cross Centres

CAD – Computer Aided Design.
Less commonly use is Computer Assisted Drafting.

CAM – Computer Aided Manufacture

CAP – Capacity

CBORE – Counterbore

CCTV – Closed Circuit TeleVision

CFW – Continuous Fillet Weld

CHAM – Chamfer

CHCL – Channel

CH HD – Cheese Head

CHS – Circular Hollow Section

CI – Cast Iron

CIRC – Circumference or Circle

C.J. OR CJ – Control Joint (or Construction Joint)

CL – Center Line

CLG – Control Joint

CLR – Clearance

CMU – Cement Masonry Unit

CNC – Computer Numerical Control

CNR – Corner

CNJ – Construction Joint

COEF – Coefficient

COL – Column

COMMS – Communications

CONC – Concentric

CONN – Connection

CONT – Continuous

CP – Chrome Plated

C REC HD – Cross-Recess Head

CRS – Colled Rolled Steel

CTRS – Centres

CS – Cleaners Sink

CS – Cast Steel

CKS – Countersink

CSK HD – Countersunk Head

CT – Controller

CTR – Contour

CTR(S) – Centre/S

CTRL – Control

CTRS – Centers

CU – Dental Cuspidor

CUP HD – Cup Head

CVR – Cover

CYL – Cylinder

°C – Degrees Celsius

D

DAR – Dressed All Round

DD – Design Drawing

DED – Dedendum

DET – Detail

DIA – Diameter

DIAG – Diagram

DIAG – Diagonal

DICL – Ductile Iron Cement Lined (pipe)

DIST – Distance

DIM – Dimension

DN – Diameter Nominal

DP – Down Pipe

DP – Diametral Pitch

DR – Dryer

DRG – Drawing

DW – Dishwasher

DWG – Drawing

DWG(S) – Drawing/S

E

E – Modulus of Elasticity

EA – Equal Angle (steel)

EF – Each Face

E.J. or EJ – Expansion Joint

EL – Elevated Level

EL – Elevation

ELEC – Electrical

ELEV – Elevation

EQ – Equal

EQUIP – Equipment

EQUIV – Equivalent

EW – Each Way

EWB – Electric Water Boiler

EWC – Electric Water Cooler

EXT – External

F

FB – Footing Beam

F’c – Characteristic Concrete Strength

FCU – Fan Coil Unit

FFL – Finished Floor Level

FHR – Fire Hose Reel

FIQ – Figure

FILL HD – Fillister Head

FL – Floor Level

FL – Flat or Flat Plate

FLG – Flange

FOC – Fibre Optic Cable

FS – Far Side

FSBL – Full Strength Butt Weld

FTG – Footing

FTP – Fibre Termination Panel (fibre optical cable)

FW – Fillet Weld

FWF – From Web Face (steel)

G

GA – General Arrangement

GALV – Galvanized

GCI – Galvanized corrugated iron.

GD – Grid

GI – Galvanized Iron

GIP – Galvanized Iron Pipe

GIS – Graphic Information System

GPO – General Purpose Outlet

GR – Grade

GRF – Geometric Reference Frame

GSM – Global System of Moblie or “Groupe Speciale Mobile” in French

H

H – Prewash Hose Reel

HD – Head

HEX HD – Hexagon Head

HEX SOC HD – Hexagon Socket Head

HOR – Horizontal

HORIZ – Horizontal

HP – High Pressure

HRA – Rockwell Hardness A

HRB – Rockwell Hardness B

HRC – Rockwell Hardness C

HS – High Strength

HT – Height

HTS – High-Tensile Steel

HV – Diamond Pyramid Hardness Number (Vickers)

HWB – Hair Wash Basin

I

I – Moment of Inertia

ID – Inside Diameter

IE – Invert Elevation

I.J. or IJ – Isolation Joint

IL – Invert Level

INT – Internal

IO – Inspection Opening

IP – Intersection Point

ISO – International Standard Organisation

J

JIS – Japanese Industry Standard

JT – Joint

JUNC – Junction

K

kHz – Kilohertz

K.J. or KJ – Key Joint

KS – Kitchen Sink

KWh – Kilo Watt Hour (metre)

L

L – Steel Angle

LAN – Local Area Network

LG – Length

LGX – Line Group Cross (Connector, fibre optical cable)

LH – Left Hand

LMC – Least Material Condition

LONG – Longitudinal

LPG – Liquid Petroleum Gas

LT – Laundry Trough

M

m – Metres (English) or Meters

MATL – Material

MAX – Maximum

M/C – Machine

MDF – Main Distribution Frame (Telecommunications)

MFR – Manufacturer

MHz – Megahertz

Micky Mouse – A toy project, of very low quality.

MI – Malleable Iron

MIN – Minimum

MISC – Miscellaneous

M.J. or MJ – Movement Joint

mm – Millimetres

MMC – Maximum Material Condition

MOD – Modification

MS – Mild Steel

MTG – Mounting

MUSH HD – Mushroom Head

N

NC – Normally Closed

NEG – Negative

NET – Network

No. – Number

NOM – Nominal

NS – Near Side

NS – Nominal Size

N.S.O.P. – Not Shown On Plan

NTS – Not To Scale

NZS – New Zealand Standard

O

OA or O/A – Overall

OCT – Octagon

OD – Outside Diameter

OPT – Optional

P

P – Pipe

PA – Pressure Angle

PAR – Parallel

PATT – Pattern

PCD – Pitch Circle Diameter

PFC – Parallel Flange Channel

PL – Plate

PL – Pipeline

POS – Positive

POSN – Position

PREFAB – Prefabricated

PT – Pressure Tapping

PT – Part

PVC – Poly Vinyl Chloride

uPVC – UV Stabilized Poly Vinyl Chloride

Q

QTY – Quantity

R

R – Radius

Ra – Roughness Value

RAD – Radius or radial

RD – Round

REF – Reference

RECT – Rectangular

REINF – Reinforcement

REQ’D or REQD – Required

REV – Revision

RH – Right Hand

RHS – Rectangular Hollow Section (rarely Rolled Holled Section)

RL – Reduced Level or Relative Level

RO – Reverse Osmosis (water treatment)

RSA – Rolled Steel Angle

RSC – Rolled Steel Channel

RSD CSK HD – Raised Countersunk Head

RSJ – Rolled Steel Joist

S

S – Snug fit or tightened (bolts)

S – Sink

SAN – Sanitary

SDU – Sanitary Disposal Unit

SECT – Section

SF – Strip Footing

SF – Spot Face

SFL – Structural Finished Level

SH – Sheet

SHR – Shower

SHS – Square Hollow Section

SIM – Similar

SK – Sketch

SL – Structural Level

SPT – Spigot

SQ – Square

SS or S/S – Stainless Steel

SSL – Structural Slab Level

ST – Steel

STD – Standard

SW – Switch

T

T – Top

TB – Tie Beam

TB – Fully tensioned, bearing type (bolts)

TEMP – Temperature

TF – Fully tensioned, friction type (bolts)

TFC – Taper Flange Channel

THD – Thread

THK – Thick

TO or T.O. or T.OFF – Top Off

TOL – Tolerance

TP – Tangent Point

TP – True Position

TP – True Profile

TR – Laundry Trough

TUN – Tundish

TYP – Typical

U

U/S – Under Side

UA – Unequal Angle (steel)

UB – Universal Beam (steel)

UC – Universal Column (steel)

UCUT – Undercut

UNO – Unless Noted Otherwise (UON is prefered)

UON – Unless Otherwise Noted

uPVC – Unplasticized Polyvinyl Chloride

UR – Urinal

V

VER – Vertical

VERT – Vertical

VOL – Volume

W

WAN – Wide Area Network

WB – Welded Beam (steel)

WC – Welded Column (steel)

WC – Water Closet (toilet).
Where the poo and wee goes.

WC(P) – Water Closet With ‘P’ Trap

WC(S) – Water Closet With ‘S’ Trap

WD – Working Drawing

WM – Washing Machine

WP – Water Proof or Work Point
WI – Wrought Iron

X

X – By. Example, “N12 x 1200 long” also means “N12 by 1200 long”.

Y

YP – Yield Point

Z

Z – Zulu (Greenwich Mean Time)

Z – Z shaped steel purlin

Z – Modulus of Section

Other Characters

°C – Degrees Celsius

Ø – Diameter

# – Number

/tb – Fully tensioned, bearing type (bolts)

/tf – Fully tensioned, friction type (bolts)

/s – Snug fit or tightened (bolts)