5/8"-18 x 2-1/2"

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.
Flange bolts

Flange bolts

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