339991: Gasket, Packing, and Sealing Device Manufacturing

What this code covers

NAICS 339991 covers gaskets, packing and sealing devices made from any material: rubber, fluorocarbon and silicone elastomers, PTFE, cork, fiber, graphite, metal and composites. Die cut, molded, machined and spiral wound products all sit here, from a flat flange gasket to an engine face seal.

Defense demand is wide and shallow: preformed packings and O-rings for hydraulic and fuel systems, engine seals, shipboard flange gaskets and pipe packing, hatch and door seals, vehicle seals, and environmental gaskets for electronics enclosures. DLA Aviation and DLA Land and Maritime manage most of them by stock number, and the volume of small buys on DIBBS is steady. Engine and airframe primes buy the same parts for production.

What federal buyers typically ask for

Most items are standard parts. O-rings follow SAE AS568 dash sizes and MS or AS part numbers, with the compound called out by a military or AMS material specification. Elastomer parts carry cure date marking and shelf life limits, and the buyer will reject a lot that is too old on arrival. A certificate of conformance with batch and cure date is standard, and a first article is common for a new source on a drawing-controlled seal.

ISO 9001 is enough for most buys, and AS9100 helps on engine and airframe seals. Metallic seals in nickel alloy can bring the DFARS specialty metals clause, while elastomer parts do not. Some engine seals are critical application items with a source approval requirement. ITAR is rare, and drawings for a named system are the exception.

Small business set-asides are the norm here. Many awards are small, automated DIBBS buys, and distributors compete alongside manufacturers, which makes the nonmanufacturer rule a live issue on set-asides. Larger long-term contracts for high-demand seals are competed among approved sources.