Drawing abbreviations
Engineering drawings abbreviate in capital letters, and in the US the accepted forms are listed by ASME Y14.38: ASSY for assembly, DWG for drawing, MATL for material, THRU for through, TYP for typical. This glossary gives the common ones, what each stands for and where it comes from, searchable by abbreviation or meaning.
Last updated
169 abbreviations, by group.
Drawings and documents
AMS
Aerospace Material Specification
SAE's material and process specifications, such as AMS 2759 for heat treating steel.
SAE
AN
Air Force-Navy
The prefix of AN standard parts.
ASME Y14.38
APPL
application
ASME Y14.38
ASSY
assembly
ASME Y14.38
AUX
auxiliary
As in an auxiliary view.
ASME Y14.38
BM
bill of material
Also written BOM.
ASME Y14.38
CAGE
Commercial and Government Entity
A five-character code for the company that owns a design, assigned by the US Defense Logistics Agency.
Defense Logistics Agency
DET
detail
ASME Y14.38
DWG
drawing
ASME Y14.38
ENLGD
enlarged
As in an enlarged view.
ASME Y14.38
FIG
figure
ASME Y14.38
FN
find number
The number in a parts list's balloons; also printed FIND NO.
ASME Y14.38
FS
far side; full size; Federal Specification; finish specification
Several meanings in the same list; where it sits tells which.
ASME Y14.38
FSCM
Federal Supply Code for Manufacturers
The older name for the CAGE code.
ASME Y14.38
IDENT
identification
As in CODE IDENT NO, the CAGE code's box on older title blocks.
ASME Y14.38
NA
next assembly; not applicable
More than one meaning in the same list; in an application block it is the next assembly.
ASME Y14.38
NHA
next higher assembly
ASME Y14.38
NO
number
As in DWG NO and FIND NO.
ASME Y14.38
NOMEN
nomenclature
ASME Y14.38
NTS
not to scale
ASME Y14.38
PIN
part or identifying number
ASME Y14.100's term for a part number; it never includes the drawing's revision.
ASME Y14.100
PL
parts list; place; plate
These and other meanings in the same list; where it sits tells which.
ASME Y14.38
PN
part number
Also printed P/N.
ASME Y14.38
SCD
specification control drawing
ASME Y14.38
SECT
section
ASME Y14.38
SH
sheet
As in SH 2 OF 3.
ASME Y14.38
SOCD
source control drawing
ASME Y14.38
SPEC
specification
ASME Y14.38
STD
standard
ASME Y14.38
SUBASSY
subassembly
ASME Y14.38
UO
used on
ASME Y14.38
Changes and approvals
APVD
approved
Title blocks also print APPD.
ASME Y14.38
DWN
drawn
Title blocks also print DR, which ASME Y14.38 gives for drill.
ASME Y14.38
ECN
engineering change notice
ASME Y14.38
ECO
engineering change order
ASME Y14.38
ECP
engineering change proposal
ASME Y14.38
ECR
engineering change request
ASME Y14.38
ENGR
engineer
ASME Y14.38
ENGRG
engineering
ASME Y14.38
EO
engineering order
ASME Y14.38
LTR
letter
The revision column's heading on older drawings.
ASME Y14.38
MFG
manufacturing
ASME Y14.38
MFR
manufacturer
ASME Y14.38
OBS
obsolete
ASME Y14.38
PRELIM
preliminary
ASME Y14.38
QA
quality assurance
ASME Y14.38
QC
quality control
ASME Y14.38
REV
revision
The title block box and the revision block column ASME Y14.35 heads REV.
ASME Y14.35
SUPSD
supersede
ASME Y14.38
SYM
symbol
Also the revision column's heading on older drawings.
ASME Y14.38
Dimensions and tolerances
APPROX
approximate
ASME Y14.38
AVG
average
ASME Y14.38
BC
bolt circle
ASME Y14.38
BSC
basic
A basic dimension is the exact value a geometric tolerance is measured from; ASME Y14.5 draws it in a box.
ASME Y14.38
C TO C
center to center
ASME Y14.38
DAT
datum
ASME Y14.38
DIA
diameter
ASME Y14.5 now puts the symbol ⌀ in front of the size instead.
ASME Y14.38
DIM
dimension
ASME Y14.38
EQL
equal
ASME Y14.38
FIM
full indicator movement
The total movement of a dial indicator on a surface, as runout is measured.
ASME Y14.38
HORIZ
horizontal
ASME Y14.38
ID
inside diameter
ASME Y14.38
LG
length
ASME Y14.38
LMC
least material condition
A feature with the least material in it: the largest hole, the smallest pin. ASME Y14.5 writes it Ⓛ in a frame.
ASME Y14.38
MAX
maximum
ASME Y14.38
MIN
minimum
ASME Y14.38
MMC
maximum material condition
A feature with the most material in it: the smallest hole, the largest pin. ASME Y14.5 writes it Ⓜ in a frame.
ASME Y14.38
NOM
nominal
ASME Y14.38
OA
overall
ASME Y14.38
OD
outside diameter
ASME Y14.38
PD
pitch diameter
ASME Y14.38
RAD
radius
ASME Y14.5 now puts R in front of the size instead.
ASME Y14.38
REF
reference
A dimension for information only, not for inspection. ASME Y14.5 now marks one by putting it in parentheses.
Common on drawings
RFS
regardless of feature size
Under ASME Y14.5 it applies wherever a tolerance has no modifier, so it is rarely written.
ASME Y14.5
THK
thick
ASME Y14.38
TIR
total indicator reading
The older name for FIM.
ASME Y14.38
TOL
tolerance
ASME Y14.38
TP
true position
Older drawings write it where ASME Y14.5 now uses the position symbol ⌖.
ASME Y14.38
TYP
typical
The dimension or note applies to every feature like the one it points at. It does not say how many, so many drawings give a count instead, such as 4X.
ASME Y14.38
UOS
unless otherwise specified
Introduces the defaults that apply wherever the drawing says nothing more particular.
ASME Y14.38
VERT
vertical
ASME Y14.38
Features and geometry
BEV
bevel
ASME Y14.38
BRK
break
ASME Y14.38
BS
both sides
ASME Y14.38
CBORE
counterbore
ASME Y14.5 shows it with the symbol ⌴.
Common on drawings
CHAM
chamfer
Common on drawings
CONC
concentric
ASME Y14.38
CSK
countersink
ASME Y14.5 shows it with the symbol ⌵.
ASME Y14.38
CYL
cylinder
ASME Y14.38
DP
depth
ASME Y14.5 shows it with the symbol ↧.
ASME Y14.38
DR
drill
In the approvals of a title block, DR means drawn.
ASME Y14.38
EXT
external
ASME Y14.38
FIL
fillet
ASME Y14.38
HEX
hexagon
ASME Y14.38
INTL
internal
Drawings also print INT.
ASME Y14.38
KWY
keyway
ASME Y14.38
LH
left hand
On a thread, one that tightens when turned counterclockwise.
ASME Y14.38
NPT
American taper pipe thread
ASME B1.20.1
NS
near side
ASME Y14.38
OPP
opposite
ASME Y14.38
PERP
perpendicular
ASME Y14.38
RH
right hand
Common on drawings
RND
round
ASME Y14.38
SPHER
spherical
ASME Y14.38
SQ
square
ASME Y14.38
SYMM
symmetrical
ASME Y14.38
TAN
tangent
ASME Y14.38
THD
thread
ASME Y14.38
THRU
through
A hole or cut that goes all the way through the part.
ASME Y14.38
TPR
taper
ASME Y14.38
UNC
Unified coarse thread series
ASME B1.1
UNEF
Unified extra-fine thread series
ASME B1.1
UNF
Unified fine thread series
ASME B1.1
Materials and hardware
AL
aluminum
ASME Y14.38
ALY
alloy
ASME Y14.38
BRKT
bracket
ASME Y14.38
BRS
brass
ASME Y14.38
CRES
corrosion-resistant steel
Another name for stainless steel, common on aerospace and defense drawings; ASME Y14.38 gives SST.
Common on drawings
CRS
cold-rolled steel
ASME Y14.38
CS
carbon steel; cast steel
These and other meanings in the same list; the material callout tells which.
ASME Y14.38
CSTG
casting
ASME Y14.38
FLG
flange
ASME Y14.38
FORG
forging
ASME Y14.38
HDW
hardware
ASME Y14.38
HRS
hot-rolled steel
ASME Y14.38
MATL
material
Title blocks also print MAT'L.
ASME Y14.38
SCR
screw
ASME Y14.38
SPR
spring
ASME Y14.38
SST
stainless steel
ASME Y14.38
STK
stock
ASME Y14.38
STL
steel
ASME Y14.38
WI
wrought iron
ASME Y14.38
WSHR
washer
ASME Y14.38
Processes and finishes
ANDZ
anodize
ASME Y14.38
ANL
anneal
ASME Y14.38
CRPL
chromium plate
ASME Y14.38
CTG
coating
ASME Y14.38
FAB
fabricate
ASME Y14.38
FAO
finish all over
ASME Y14.38
FNSH
finish
Title blocks often spell it out: FINISH.
ASME Y14.38
GALV
galvanize
ASME Y14.38
HDN
harden
ASME Y14.38
HDNS
hardness
ASME Y14.38
HTTR
heat-treat
ASME Y14.38
INSP
inspect
ASME Y14.38
INSTL
install
ASME Y14.38
MACH
machine
ASME Y14.38
PLD
plated
ASME Y14.38
PLTG
plating
ASME Y14.38
PNT
paint
ASME Y14.38
POL
polish
ASME Y14.38
PRMR
primer
ASME Y14.38
PSVT
passivate
ASME Y14.38
TEM
temper
ASME Y14.38
TRTMT
treatment
ASME Y14.38
WLD
welded
ASME Y14.38
Quantities and units
ALTN
alternate
ASME Y14.38
AR
as required
In a parts list, a quantity set at assembly, such as adhesive or shims.
ASME Y14.38
DEG
degree
ASME Y14.38
EA
each
ASME Y14.38
FT
foot
ASME Y14.38
IN
inch
ASME Y14.38
INCL
inclusive
ASME Y14.38
LB
pound
ASME Y14.38
QTY
quantity
ASME Y14.38
REQD
required
As in QTY REQD, a parts list's quantity column.
ASME Y14.34
VAR
variable
ASME Y14.38
WO
without
Also printed W/O.
ASME Y14.38
WT
weight
ASME Y14.38
No abbreviation matches that. Try the letters, such as TYP, or a word from the meaning.
154 of the 169 entries are checked against the list in ASME Y14.38's 1999 edition, letters and meaning both; the standard was reissued in 2007 and 2019, so check an entry against the current edition before writing it on a new drawing. The others name the standard they come from, or are marked as common on drawings. Abbreviations we could not confirm are left out.
How to read them
Reading abbreviations on a drawing.
Most abbreviations explain themselves once you know the list; the trouble comes from the few that mean more than one thing, and from forms the list does not have.
- Read them where they sit. The same letters can mean different things: FS, PL, NA and CS each have several meanings in ASME Y14.38, and DR is drill in the list but drawn in the approvals of some title blocks.
- Title blocks print house forms. A caption is often the company's own: CHK, CHKD or CHECKED for the same box. The title block guide lists the usual captions.
- Symbols replaced some. ASME Y14.5 puts ⌀ for diameter and R for radius in front of a size, uses ⌴ for counterbore, ⌵ for countersink and ↧ for depth, writes 4X for four places, and puts a reference dimension in parentheses.
- Older drawings use older forms. TIR where newer ones say FIM, TP for true position, FSCM for the CAGE code.
Sources: ASME Y14.38 (abbreviations), ASME Y14.5 (dimensioning symbols).
Questions
What people ask about drawing abbreviations.
What standard covers abbreviations on engineering drawings?
In the US, ASME Y14.38, Abbreviations and Acronyms for Use in Product Definition and Related Documents; its 2019 edition followed those of 1999 and 2007. It lists the accepted form of each abbreviation, though a company may still print its own forms in its title blocks.
What does TYP mean on a drawing?
Typical. The dimension or note applies to every feature like the one it points at. It does not say how many, so many drawings give a count instead, such as 4X.
What does THRU mean on a drawing?
Through: a hole or cut that goes all the way through the part, so it has no depth to give.
What is the difference between CRES and SST?
None in meaning: both are stainless steel. SST is the abbreviation ASME Y14.38 gives; CRES, corrosion-resistant steel, is common on aerospace and defense drawings.
What does REF mean on a drawing?
Reference. A dimension for information only, not for inspection. ASME Y14.5 now marks one by putting it in parentheses.
Why does one abbreviation mean different things?
Because the list is long and the letters are few. In ASME Y14.38, FS can mean far side, full size, Federal Specification or finish specification, and PL parts list, place or plate. Where the abbreviation sits tells which: PL over a column of parts is a parts list, 2 PL beside a dimension is two places.
From SpecCapture
Abbreviations in every box?
SpecCapture reads the title block, the revision history, the bill of materials, the hole table, the application block, the tabulated dash numbers and the general notes off 2D engineering drawings, with a box on the drawing around every value it reads, so checking it takes a glance.