We had slightly over 100,000 pieces of these serrated custom hex flange bolts manufactured for our construction customer to their drawing specifications and tolerances. They were manufactured per SAE J429 Grade 5 requirements with Zinc Clear finish per ASTM B633. Flange OD was set to .68″ and across the flats dimension to .489-.500″. The screws were fully threaded with 5/16-18 2a thread at 2-1/2″ in length. Full certs were provided including 3rd party testing for proof load, hardness, and chemical composition requirements.