US Fasteners

Wood screw

Wood screws

Screws with a smooth shank and tapered point for use in wood.
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.
Nut

Nuts

Nuts have internal machine threads, for use with machine thread bolts and screws.