1/2"-20 x 3" ASTM A574 Hex Drive Black Oxide Finish Alloy Steel Socket Cap Screw / THREAD CLASS: 3A THREAD DIRECTION: RIGHT-HAND FASTENER LENGTH: 3.496 INCHES NOMINAL END ITEM IDENTIFICATION: 2320-01-465-2174 THREAD QUANTITY PER INCH: 20 SPECIAL FEATURES: PHOSPHATE AND OIL FINISH MATERIAL DOCUMENT AND CLASSIFICATION: SAE J429 GR8 ASSN STD ALL MATERIAL RESPONSES OVERALL THREAD SERIES DESIGNATOR: UNC