-389 BLACK BUNA 90D O-RING

Part number H90389 is an AS568-389 black Buna-N (Nitrile) 90 Shore A O-Ring measuring an inside diameter of 19.953 in (506.81 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 20.373 in (517.47 mm). An o-ring delivers dependable bidirectional sealing in a compact groove envelope.

The compound resists propane and butane, petroleum-based oils, and hydraulic fluids. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for 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 should not be specified for service in strong acids or automotive brake fluid.

It sees regular use in fluid power, agricultural equipment, and automotive.

Reference part number H90389 when ordering; the item is sold individually. Unit weight is approximately 47.08 g and nominal inside diameter is listed as 20 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.