Q-040 BUNA 70 Q RING

Part number QH70040 is an AS568-040 black Buna-N (Nitrile) 70 Shore A Quad-Ring built to an inside diameter of 2.864 in (72.75 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 3.004 in (76.3 mm). A quad-ring provides a dual sealing band on each contact face for improved reliability.

As a material, Buna-N (Nitrile) is widely chosen for low compression set under sustained load, strong abrasion and tear resistance. It resists petroleum-based oils, propane and butane, and hydraulic fluids. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Exposure to ozone and direct sunlight or ketones will shorten service life. The profile itself contributes two sealing bands per contact face rather than one and resistance to the spiral twisting that defeats round-section rings.

Maintenance and OEM teams specify it across construction equipment, general industrial maintenance, and hydraulic and pneumatic systems.

Reference part number QH70040 when ordering; the item is sold individually. Unit weight is approximately 0.753 g and nominal inside diameter is listed as 2 7/8 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.