1/4"-28 x 3" ASTM A574 Hex Drive Zinc Finish Alloy Steel Socket Cap Screw / THREAD CLASS: 3A THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 1.00 INCHES NOMINAL FASTENER LENGTH: 2.94 INCHES MINIMUM AND 3.00 INCHES MAXIMUM HEAD STYLE: C44 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: 2590-01-588-5057 NOMINAL THREAD DIAMETER: 0.250 INCHES WIDTH ACROSS FLATS: 0.190 INCHES NOMINAL THREAD QUANTITY PER INCH: 28 MATERIAL: STEEL UNS K03104 OVERALL MATERIAL DOCUMENT AND CLASSIFICATION: PER ASTM A574 NATIONAL STD/SPEC SINGLE MATERIAL RESPONSE OVERALL SURFACE TREATMENT: ZINC OVERALL SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: PER ASTM F1941 NATIONAL STD/SPEC SINGLE TREATMENT RESPONSE OVERALL THREAD SERIES DESIGNATOR: UNRF