5/16"-18 x 3" Hot Dipped Galvanized Finish ASTM A307 Grade A Round Head Carriage Bolt / THREAD DIRECTION: RIGHT-HAND FASTENER LENGTH: 3.00 INCHES NOMINAL HEAD STYLE: C31 OVAL END ITEM IDENTIFICATION: 2330-016033559 NOMINAL THREAD DIAMETER: 0.3125 INCHES THREAD QUANTITY PER INCH: 18 PART NAME ASSIGNED BY CONTROLLING AGENCY: SCREW, CARRIAGE SPECIAL FEATURES: SURFACE TREATMENT IS HOT DIPPED GALVANIZED MATERIAL: STEEL CORROSION RESISTING OVERALL THREAD SERIES DESIGNATOR: UNC