Q-387 BUNA 70 Q RING

Part number QH70387 is an AS568-387 black Buna-N (Nitrile) 70 Shore A Quad-Ring supplied with an inside diameter of 17.955 in (456.06 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 18.375 in (466.73 mm). A quad-ring provides a dual sealing band on each contact face for improved reliability.

This material stands up to petroleum-based oils, water, and propane and butane. Buna-N (Nitrile) is specified for reliable performance in both static and dynamic service, low compression set under sustained load. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Exposure to automotive brake fluid or strong acids will shorten service life. The profile itself contributes a parting line located away from the sealing surface and lower compressive load required to achieve a seal.

Maintenance and OEM teams specify it across hydraulic and pneumatic systems, general industrial maintenance, and fluid power.

QH70387 ships individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.