1/4"-20 x 1-1/2" ASTM A574 Hex Drive Zinc Finish Alloy Steel Socket Cap Screw / THREAD CLASS: 3A THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 0.500 INCHES NOMINAL FASTENER LENGTH: 1.460 INCHES MINIMUM AND 1.500 INCHES MAXIMUM HEAD STYLE: C48 FLAT FILLISTER HEAD DIAMETER: 0.365 INCHES MINIMUM AND 0.375 INCHES MAXIMUM HEAD HEIGHT: 0.244 INCHES MINIMUM AND 0.250 INCHES MAXIMUM INTERNAL DRIVE STYLE: D5 HEXAGON END ITEM IDENTIFICATION: 2320-01-564-6882 TRUCK TRACTOR NOMINAL THREAD DIAMETER: 0.250 INCHES WIDTH ACROSS FLATS: 0.188 INCHES NOMINAL THREAD QUANTITY PER INCH: 20 PART NAME ASSIGNED BY CONTROLLING AGENCY: SOCKET CAP SCREW MATERIAL: STEEL OVERALL MATERIAL DOCUMENT AND CLASSIFICATION: ASTM A574 ASSN STD SINGLE MATERIAL RESPONSE OVERALL SURFACE TREATMENT: ZINC OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: ASTM F1941, FE/ZN 3AT ASSN STD SINGLE TREATMENT RESPONSE OVERALL THREAD SERIES DESIGNATOR: UNRC