5/16″-18 x 2-1/4″ Green Rinsed Zinc Grade 5 Hex Cap Screws (188 pcs.)
Diameter: 5/16″ Length: 2-1/4″ Material: Steel Finish: Green Rinsed Zinc Head Style: Hex (1/2″ Wrench) Thread Size: 18 (Coarse) Thread Length: 7/8″ Hardness: Grade 5 Type: Cap Screw Box of 188. A hex cap screw has a hexagonal head, designed to be driven by a wrench.