5/16"-18 x 1/2" Zinc Finish SAE J429 Grade 8 Hex Serrated Flange Bolt / THREAD CLASS: 2A THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 0.500 INCHES NOMINAL FASTENER LENGTH: 0.500 INCHES NOMINAL HEAD STYLE: C7 HEXAGON EXTENDED WASHER END ITEM IDENTIFICATION: 4320-01-617-7587 NOMINAL THREAD DIAMETER: 0.312 INCHES THREAD QUANTITY PER INCH: 18 PART NAME ASSIGNED BY CONTROLLING AGENCY: HEX HEAD SERRATED FLANGE SCREW MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL THREAD SERIES DESIGNATOR: UNC