5/16"-18 x 1" (8 pcs.)

Diameter: 5/16"
Length: 1"
Material: Steel
Finish: Zinc
Driver Type: 1/2" Wrench
Thread Size: 18 (Coarse)
Thread Length: Full
Hardness: Grade 5
Type: Cap Screw

Box of 8.

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