Q-309 BUNA 70 Q RING

Part number QH70309 is an AS568-309 black Buna-N (Nitrile) 70 Shore A Quad-Ring supplied with an inside diameter of 0.412 in (10.46 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 0.832 in (21.13 mm). A quad-ring provides a dual sealing band on each contact face for improved reliability.

The compound resists greases and lubricants, hydraulic fluids, and water. That behavior comes from the compound itself: Buna-N (Nitrile) is specified for low compression set under sustained load, reliable performance in both static and dynamic service. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Applications involving ketones or polar solvents call for a different compound. The profile itself contributes resistance to the spiral twisting that defeats round-section rings and two sealing bands per contact face rather than one.

Common environments for this compound include general industrial maintenance, agricultural equipment, and fluid power.

Order part number QH70309, sold individually. Check the compound against your process media, pressure and temperature before committing to a design. For a size or compound outside the standard catalog, APG can quote from a print or sample.