1/4"-20 x 3/4" Hex - Slotted Indented Hex Washer Head Zinc Finish Type F Point Steel Thread Cutting Screw / THREAD CLASS: TYPE F THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 0.720 INCHES MINIMUM AND 0.750 INCHES MAXIMUM FASTENER LENGTH: 0.720 INCHES MINIMUM AND 0.750 INCHES MAXIMUM HEAD STYLE: C7 HEXAGON EXTENDED WASHER HEAD HEIGHT: 0.172 INCHES MINIMUM AND 0.190 INCHES MAXIMUM WIDTH BETWEEN FLATS: 0.367 INCHES MINIMUM AND 0.375 INCHES MAXIMUM EXTENDED WASHER DIAMETER: 0.480 INCHES MINIMUM AND 0.520 INCHES MAXIMUM EXTENDED WASHER THICKNESS: 0.030 INCHES MINIMUM AND 0.050 INCHES MAXIMUM END ITEM IDENTIFICATION: 2355-01-567-4930 TRUCK, BOMB SERVICE NOMINAL THREAD DIAMETER: 0.250 INCHES THREAD QUANTITY PER INCH: 20 PART NAME ASSIGNED BY CONTROLLING AGENCY: SLOTTED INDENTED HEX WASHER HEAD THREAD CUTTING SCREW, TYPE F MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: ASTM F1941, FE/ZN ASSN STD SINGLE TREATMENT RESPONSE OVERALL THREAD SERIES DESIGNATOR: UNC