Fastener Categories

Wood Screws
Screws with a smooth shank and tapered point for use in wood.
Abbreviated WS

Machine Screws
Screws with threads for use with a nut or tapped hole.
Abbreviated MS

Sheet Metal Screws
Fully threaded screws with a point for use in sheet metal.
Abbreviated SMS

Self Drilling SMS
A Sheet metal screw with a self drilling point.
 

Hex Bolts
Bolts with a hexagonal head with threads for use with a nut or tapped hole.
Abbreviated HHMB or HXBT

Carriage Bolts
Bolts with a smooth rounded head that has a small square section underneath.

Lag Bolts
Bolts with a wood thread
and pointed tip.
Abbreviated Lag

Set Screws
Machine screws with no head for screwing all the way into threaded holes.

Head Styles

Flat
A countersunk head with a flat top.
Abbreviated FH

Oval
A countersunk head with a rounded top.
Abbreviated OH or OV

Pan
A slightly rounded head with short vertical sides.
Abbreviated PN

Truss
An extra wide head with a rounded top.
Abbreviated Truss

Round
A domed head.
Abbreviated RH

Hex
A hexagonal Head.
Abbreviated HH or HX

Hex Washer
A hex head with built
in washer.

Slotted Hex Washer
A hex head with built in washer and a slot.

Drive Types

Phillips and Frearson
An X shaped drive.
Abbreviated PH

Slotted
A slot in the head.
Abbreviated SL

Combination
A combination of slotted and Phillips drives.
Abbreviated Combo

Socket or Allen
A hexagonal hole for use with and Allen wrench.

Hex
A six sided nut. Also referred to as a finished hex nut.

Nylon Insert Lock
A nut with a nylon insert
to prevent backing off.
Also referred to as a Nylock

Jam
A hex nut with a reduced height.

Nylon Insert Jam Lock
A nylock nut with a reduced height.

Wing
A nut with 'wings' for hand tightening.

Cap or Acorn
A nut with a domed top over the end of the fastener.

Flange
A nut with a built in washer like flange.

Kep
A nut with a built in external tooth lock washer, used to speed up assembly.

 

Tee
A nut designed to be driven into wood to create a threaded hole.

Square
A four sided nut.

Prevailing torque lock
A non-reversible nut used for high temperature applications

Washer Types

Flat
A flat washer used to
distribute load. vailable in SAE, USS, and other patterns.

Fender
An oversize flat washer used to further distribute load especially on soft materials.

Finishing
A washer used to obtain a 'finished' look. Usually used with oval head screws.

Split Lock
The most common style of washer used to prevent nuts and bolts from backing out.

 

External Tooth Lock
A washer with external 'teeth' Used to prevent nuts and bolts from backing out.

Internal Tooth Lock
A washer with internal 'teeth' Used to prevent nuts and bolts from backing out.

Square
A square shaped washer.