Bolt Depot - Chart of Nut, Bolt and Screw Types

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Fastener Information

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Fastener Type Chart

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.

Socket Screws
Socket screws, also known as Allen head are fastened with a hex Allen wrench.

Eye Bolts
A bolt with a circular ring on the head end. Used for attaching rope or chain.

Eye Lags
Similar to an eye bolt but with wood threads instead of machine thread.

U-Bolts
Bolts in U shape for attaching to pipe or other round surfaces. Also available with a square bend.

J-Bolts
J shaped bolts are used for tie-downs or as an open eye bolt.

Hanger Bolts
Hanger bolts have wood thread on one end and machine thread on the other end.

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.

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.

Socket Cap
A small cylindrical head using a socket drive.

Button
A low profile rounded head using a socket drive.

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, Hex or Allen
A hexagonal hole for use with an Allen wrench.

Nut Types

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

Acorn
Acorn nuts are a high crown type of cap nut, used for appearance.

Flange
A nut with a built in washer like flange.

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 lock nut used for high temperature applications

K-Lock or Kep
A nut with an attached free-spinning external tooth lockwasher.

Coupling
Coupling nuts are long nuts used to connect pieces of threaded rod or other male threaded fasteners.

Washer Types

Flat
A flat washer used to
distribute load. Available 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.

Dock
Dock washers have a larger outside diameter and are thicker than standard.

Ogee
Thick, large diameter, cast iron washers with a curved or sculpted appearance. Typically used in dock and wood construction