5/16"-18 x 1" ASTM F593 18-8 Stainless Steel Round Head Carriage Bolt / THREAD CLASS: 2A THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 1.000 INCHES NOMINAL FASTENER LENGTH: 1.161 INCHES MINIMUM HEAD STYLE: C36 FLAT WASHER HEAD DIAMETER: 0.688 INCHES MINIMUM AND 0.719 INCHES MAXIMUM HEAD HEIGHT: 0.156 INCHES MINIMUM AND 0.176 INCHES MAXIMUM NOMINAL THREAD DIAMETER: 0.563 INCHES THREAD QUANTITY PER INCH: 18 PART NAME ASSIGNED BY CONTROLLING AGENCY: 5/16-18X1 STAINLESS STEEL CARRAGE BOLT MATERIAL: STEEL CORROSION RESISTING OVERALL THREAD SERIES DESIGNATOR: UNC