US Fasteners

Wood screw

Wood screws

Screws with a smooth shank and tapered point for use in wood.
Sheet metal screw

Sheet metal screws

Screws with large threads for use in sheet metal sometimes also used in plastic, fiberglass, or wood.
Hex bolt

Hex bolts

Bolts with hexagonal heads and machine threads for use with a nut or in a tapped hole. Also known as hex cap screws or machine bolts.
Flange bolts

Flange bolts

Flange bolts have a flange on the bottom of the head that distributes the load like a washer.
Machine screw

Machine screws

Screws with machine threads for use with a nut or in a tapped hole.
Socket product

Socket screws

Screws with an allen wrench drive.
Set screw

Set screws

Screws with no head and machine threads for use in a tapped hole.
Eye bolts

Eye bolts & Screw eyes

Bolts or screws with a circular ring on the head.
Spacer

Spacers

Unthreaded sleeves that fit over bolts or screws to maintain space between components.
Sex bolt & Mating screw

Sex bolts & Mating screws

Sex bolts resemble machine screws, but with internal threads, and can be used with either specialized mating screws or standard machine screws. Also known as barrel nuts and Chicago bolts.
Shoulder bolt

Shoulder bolts

Screws with an unthreaded shoulder that is larger in diameter than the threads. Also known as stripper bolts.
Cotter pin

Cotter pins

Cotter or split pins have two tines which are bent apart to hold them in place.