Hex Head Cap Screw Head Type Hex Diameter 9/16 In. Grade 8 Material Medium Carbon Steel Finish Plain Thread Size 9/16-18 Thread Type Fine Length under Head 5-1/2 In. Thread Length 1-3/8 In. Head Height 23/64 In. Head Width 13/16 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 ASME B18.2.1 Refills Mfr No 00081-2952-450 Package Quantity 75