5/16"-18 x 1-3/4" SAE J429 Grade 8 Yellow Zinc Finish Steel Tap Bolt / THREAD CLASS: 2A THREAD DIRECTION: RIGHT-HAND THREAD LENGTH: 1.71 INCHES MINIMUM AND 1.77 INCHES MAXIMUM FASTENER LENGTH: 1.71 INCHES MINIMUM AND 1.77 INCHES MAXIMUM HEAD STYLE: C1 HEXAGON HEAD HEIGHT: 0.20 INCHES MINIMUM AND 0.24 INCHES MAXIMUM WIDTH BETWEEN FLATS: 0.48 INCHES MINIMUM AND 0.50 INCHES MAXIMUM END ITEM IDENTIFICATION: 2320-01-465-2174 NOMINAL THREAD DIAMETER: 0.3125 INCHES THREAD QUANTITY PER INCH: 18 CHAMFER ANGLE: 15.0 DEGREES MINIMUM AND 30.0 DEGREES MAXIMUM COLOR: YELLOW OVERALL MATERIAL: STEEL OVERALL SURFACE TREATMENT: ZINC OVERALL THREAD SERIES DESIGNATOR: UNC