Diameter: 5/8"
Length: 3"
Material: Steel
Finish: Green Rinsed Zinc
Head Style: Hex (15/16" Wrench)
Thread Size: 18 (Fine)
Thread Length: 1-1/2"
Hardness: Grade 5
Type: Cap Screw

Box of 16.

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