1/4"-28 x 5/16" Hex Drive Cone Point Black Oxide Finish Alloy Steel Socket Set Screw / THREAD CLASS: 2A THREAD DIRECTION: RIGHT-HAND FASTENER LENGTH: 0.3125 INCHES NOMINAL HEAD STYLE: C101 HEADLESS (SETSCREW) POINT STYLE: F16 CONE INTERNAL DRIVE STYLE: D5 HEXAGON NOMINAL THREAD DIAMETER: 0.75 INCHES WIDTH ACROSS FLATS: 0.1250 INCHES MINIMUM AND 0.1270 INCHES MAXIMUM THREAD QUANTITY PER INCH: 28 MATERIAL: STEEL OVERALL THREAD SERIES DESIGNATOR: UNF