1/2"-13 x 3/4" Slotted Drive Undercut Flat Head Zinc Finish Steel Machine Screw / THREAD DIRECTION: RIGHT-HAND FASTENER LENGTH: 0.750 INCHES NOMINAL HEAD STYLE: A39 FLAT COUNTERSUNK INTERNAL DRIVE STYLE: B10 SLOT NOMINAL THREAD DIAMETER: 0.250 INCHES THREAD QUANTITY PER INCH: 13 SCREW MATERIAL: STEEL SCREW SURFACE TREATMENT: ZINC THREAD SERIES DESIGNATOR: UNC