5/16″-18 x 4-1/2″ Zinc Grade 5 Hex Cap Screws (50 pcs.)
Diameter: 5/16″ Length: 4-1/2″ Material: Steel Finish: Zinc Head Style: Hex (1/2″ Wrench) Thread Size: 18 (Coarse) Thread Length: 7/8″ Hardness: Grade 5 Type: Cap Screw Box of 50. A hex cap screw has a hexagonal head, designed to be driven by a wrench.