Collection: O-Rings

Aircraft O-rings seal fuel, hydraulic and pneumatic systems against pressure, temperature and aggressive fluids. Dash numbers follow the AS568 size standard; the military specification on top of it fixes the elastomer compound and qualification.

Key families: MS29512/MS29513 for fuel systems, MS28775 for hydraulic service, and the AN6227/AN6230 series on legacy drawings. Compounds include nitrile (Buna-N) for petroleum fluids, fluorocarbon for wide temperature and synthetic-fluid resistance, silicone for static and low-temperature seals, and EPR for phosphate-ester hydraulic fluids. Compound selection is not interchangeable — the fluid and the spec decide, and the wrong elastomer swells, hardens or dissolves in service.

Every lot ships with a Certificate of Conformance; heat-lot traceable mill material reports are available on request. Made to order, ships in 4 weeks, delivered duty paid — US duties included in our prices, with free express shipping on orders of $300 or more. Sold by the piece (EA), 1-piece minimum.

O-ring sizes and compounds are being added continuously. Send the part number or AS568 dash number — we quote within one business day.