*Q-203 BUNA 70 Q RING

Ordered as QH70203, this is an AS568-203 black Buna-N (Nitrile) 70 Shore A Quad-Ring measuring an inside diameter of 0.296 in (7.52 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.574 in (14.58 mm). The quad-ring uses a four-lobed profile to create two sealing surfaces per side, reducing the squeeze needed to seal.

Expect good resistance to hydraulic fluids, water, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for strong abrasion and tear resistance, low compression set under sustained load. 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 two sealing bands per contact face rather than one and resistance to the spiral twisting that defeats round-section rings.

Common environments for this compound include fluid power, automotive, and construction equipment.

Stocked as QH70203 and sold individually. Unit weight is approximately 0.444 g. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.