US, 1/4"-20 x 1-5/8"

US Fasteners

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.
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.