Hex Head Cap Screw Head Type Flange Diameter 5/8 In. Grade 8 Material Alloy Steel Finish Plain Thread Size 5/8-18 Thread Type Fine Length under Head 3-1/2 In. Thread Length 1-1/2 In. Head Height 5/8 In. Head Width 15/16 In. Flange Dia 1-21/64 In. Thread Style Partially Threaded Thread Direction Right Hand Proof Load 120 000 psi Tensile Strength 150 000 psi Rockwell Hardness C33 to C39 Meets/Exceeds SAE J429 IFI-111 Package Quantity 15