Optional gaskets prevent metal-to-metal contact and improve performance.., Material Test Reports Supplied, 3-A Certified, CRN Certified 15W - THREADED BEVEL SEAT FERRULE TANK SPUD (HEAVY) - 1", These stainless steel sanitary fittings utilize a plain bevel ferrule mating to a threaded bevel ferrule and held in place with a captured hex nut creating a leak-proof, secure, and rigid connection.