5/16"-18 x 2-1/2" Nylon Plastic Coarse Thread Hex Cap Screws

Diameter: 5/16"
Length: 2-1/2"
Material: Nylon
Head Style: Hex (1/2" Wrench)
Thread Size: 18 (Coarse)
Thread Length: 1"
Type: Cap Screw

Box of 8.

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