5/16"-18 x 1-1/2" Grade 8 Yellow Zinc Finish Hex Cap Screw / THREAD CLASS: 2A THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 0.875 INCHES NOMINAL FASTENER LENGTH: 1.400 INCHES MINIMUM AND 1.500 INCHES MAXIMUM HEAD STYLE: C1 HEXAGON HEAD HEIGHT: 0.195 INCHES MINIMUM AND 0.211 INCHES MAXIMUM WIDTH BETWEEN FLATS: 0.489 INCHES MINIMUM AND 0.500 INCHES MAXIMUM NOMINAL THREAD DIAMETER: 0.312 INCHES THREAD QUANTITY PER INCH: 18 PART NAME ASSIGNED BY CONTROLLING AGENCY: 5/16 INCHES-18X1-1/2 INCHES GRADE 8 YELLOW ZINC HEX CAP SCREW SPECIAL FEATURES: MATERIAL STEEL GRADE 8 COLOR: YELLOW OVERALL MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL THREAD SERIES DESIGNATOR: UNC