1/2"-13 x 4" Grade 5 Zinc Finish Hex Cap Screw / THREAD CLASS: 2A THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 1.250 INCHES NOMINAL FASTENER LENGTH: 4.000 INCHES NOMINAL HEAD STYLE: C1 HEXAGON HEAD HEIGHT: 0.302 INCHES MINIMUM AND 0.323 INCHES MAXIMUM WIDTH BETWEEN FLATS: 0.736 INCHES MINIMUM AND 0.750 INCHES MAXIMUM END ITEM IDENTIFICATION: 2590-01-626-1871 NOMINAL THREAD DIAMETER: 0.500 INCHES THREAD QUANTITY PER INCH: 13 PART NAME ASSIGNED BY CONTROLLING AGENCY: SCREW, CAP, HEX (FINISHED HEX BOLT) SPECIAL FEATURES: MATERIAL GRADE 5 MATERIAL: STEEL OVERALL SURFACE TREATMENT: PASSIVATE OVERALL THREAD SERIES DESIGNATOR: UNC