Q-355 BUNA 70 Q RING

Part number QH70355 is an AS568-355 black Buna-N (Nitrile) 70 Shore A Quad-Ring with an inside diameter of 5.225 in (132.72 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.645 in (143.38 mm). A quad-ring resists spiral failure in reciprocating service thanks to its multi-lobe geometry.

As a material, Buna-N (Nitrile) is valued for reliable performance in both static and dynamic service, low compression set under sustained load. This material stands up to many alcohols, propane and butane, and petroleum-based oils. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Exposure to automotive brake fluid or strong acids will shorten service life. The profile itself contributes lower compressive load required to achieve a seal and resistance to the spiral twisting that defeats round-section rings.

It sees regular use in construction equipment, hydraulic and pneumatic systems, and automotive.

Reference part number QH70355 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 1/4 inch. Review your operating media and conditions against this specification before installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.