1/2"-20 x 4-1/2" ASTM A574 Hex Drive Black Oxide Finish Alloy Steel Socket Cap Screw - HoloKrome USA / THREAD CLASS: 2A THREAD DIRECTION: RIGHT-HAND FASTENER LENGTH: 4.500 INCHES NOMINAL HEAD STYLE: C49 FLAT CHAMFER NOMINAL THREAD DIAMETER: 0.500 INCHES THREAD QUANTITY PER INCH: 20 MATERIAL: STEEL OVERALL MATERIAL DOCUMENT AND CLASSIFICATION: HOLO-KROME, CAGE 49181 MFR REF SINGLE MATERIAL RESPONSE OVERALL THREAD SERIES DESIGNATOR: UNF