Button

US Fasteners

Star pin-in button head sheet metal screws

Sheet metal screws

Screws with large threads for use in sheet metal sometimes also used in plastic, fiberglass, or wood.
Star pin-in button head machine screws

Machine screws

Screws with machine threads for use with a nut or in a tapped hole.
Socket button head screw

Socket screws

Screws with an allen wrench drive.
Socket button head sex bolt

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.
US fastener assortment

Assortments

Fastener assortments in U.S. Sizes.

Metric Fasteners

Metric socket button head screw

Socket screws

Screws with an allen wrench drive.