-391 BLACK BUNA 70D O-RING

Ordered as H70391, this is an AS568-391 black Buna-N (Nitrile) 70 Shore A O-Ring measuring an inside diameter of 21.953 in (557.61 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 22.373 in (568.27 mm). The o-ring delivers dependable bidirectional sealing in a compact groove envelope.

The material holds up against hydraulic fluids, propane and butane, and many alcohols. That behavior comes from the compound itself: Buna-N (Nitrile) offers low compression set under sustained load, reliable performance in both static and dynamic service. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. It is not the right choice where strong acids or ketones are present.

Maintenance and OEM teams specify it across agricultural equipment, hydraulic and pneumatic systems, and construction equipment.

Stocked as H70391 and sold individually. Unit weight is approximately 48.1918 g. Check the compound against your process media, pressure and temperature before committing to a design. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.