5/16-18 Case Hardened Zinc Plated Serrated Large Hex Flange Nut / THREAD CLASS: 2B THREAD DIRECTION: RIGHT-HAND WASHER OUTSIDE DIAMETER: 0.790 INCHES MINIMUM AND 0.820 INCHES MAXIMUM OVERALL HEIGHT: 0.343 INCHES MINIMUM AND 0.375 INCHES MAXIMUM NUT STYLE: A294 HEXAGON WASHER THICKNESS: 0.040 INCHES NOMINAL END ITEM IDENTIFICATION: 3825-01-577-2713 DISTRIBUTOR, WATER, TANK TYPE WIDTH ACROSS FLATS: 0.489 INCHES MINIMUM AND 0.500 INCHES MAXIMUM THREAD SERIES: UNC THREAD QUANTITY PER INCH: 18 NOMINAL THREAD SIZE: 0.313 INCHES PART NAME ASSIGNED BY CONTROLLING AGENCY: HEX LARGE FLANGE NUT, SERRATED MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: ASTM F1941, FE/ZN 3 AT ASSN STD SINGLE TREATMENT RESPONSE OVERALL