12mm, 18-8

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.

Screws with an Allen wrench drive.

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

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

A fully threaded rod with no head or drive. Commonly used in manufacturing, automotive, electrical, plumbing, and general construction applications.