5/16"-18 x 1-3/4" Black Chrome Plated Steel Coarse Thread Hex Cap Screws

Diameter: 5/16"
Length: 1-3/4"
Material: Steel
Finish: Black Chrome
Head Style: Hex (1/2" Wrench)
Thread Size: 18 (Coarse)
Thread Length: 1" to 2"
Type: Cap Screw

Box of 5.

A hex cap screw has a hexagonal head, designed to be driven by a wrench.