Common Fastener Related Abbreviations
| Abbreviation | Meaning |
&NT |
With Nut |
AN |
Precedes a dimensional specification for aircraft fasteners developed by the Aeronautical Standards Group. |
ASTM |
American Society for Testing and Materials. Used preceding a standard number developed by that group. |
BR |
Brass |
BSF |
British Standard Fine |
BSW |
British Standard Whitworth |
BT |
Bolt (on drawings) |
C |
National Coarse Thread |
CL |
Class (Metric Material/Strength Specification) |
CR |
Chrome |
CSS |
Counter Sunk Screw (flat or oval head) |
CT |
Course Thread |
DIN |
An abbreviation for Deutsches Institut für Normung, the German standards body. In reference to fasteners DIN indicates fasteners that conform to a specific metric standard (will be followed by the standard number). |
F |
Fully Threaded |
FH |
Flat Head |
FIL |
Fillister Head |
FIN |
Finishing (Washer) |
FNDR |
Fender (Washer) |
FT |
Fine Thread, Fully Threaded |
G |
Grade |
Galv. |
Galvanized |
Galvi |
Galvanized |
GR |
Grade |
GV |
Galvanized |
HD |
Head |
HHMB |
Hex Head Machine Bolt |
HVHX |
Heavy Pattern Hex Bolt |
HX |
Hex |
JMNT |
Jam Nut |
LB |
Lag Bolt, weight in pounds |
| LH | Left Hand Thread |
LW |
Lock Washer |
M |
Metric |
MB |
Machine Bolt |
MS |
Machine Screw |
MSNT |
Machine Screw Nut |
NC |
National Coarse Thread |
NF |
National Fine Thread |
NT |
Nut |
OH |
Oval Head |
OV |
Oval Head |
P |
Philips |
PH |
Philips Head |
Phil. |
Philips Drive |
PN |
Pan Head |
PT |
Partial Thread |
RD |
Round Head |
RH |
Round Head, or Right Hand Thread |
| S | Slotted |
S/S |
Stainless Steel |
SAE |
SAE Pattern (Washers) These washers have a smaller outside diameter than USS pattern washers, Also used to indicate US Fine Thread |
SBR |
Silicon Bronze |
SD |
Square Drive |
SEMS |
A type of pre-made screw and washer assembly |
SKT |
Socket |
SL |
Slotted |
Slot. |
Slotted Drive |
SMS |
Sheet Metal Screw |
SQ |
Square |
SS |
Stainless Steel, Set Screw |
USS |
USS Pattern (washers). These washers have a larger outside diameter than SAE pattern washers, Also used to indicate US Course Thread |
WS |
Wood Screw |
Z |
Zinc |
