Hex Head Cap Screw Head Type Hex Diameter 5/16 In. Grade Non Graded Material Nylon Finish Plain Thread Size 5/16-18 Thread Type Coarse Length under Head 1 In. Thread Length 1 In. Head Height 15/64 In. Head Width 1/2 In. Thread Style Fully Threaded Thread Direction Right Hand Proof Load 55 000/33 000 psi Tensile Strength 403 psi Rockwell Hardness M61 Meets/Exceeds IFI Package Quantity 10