8-165 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90165, an AS568-165 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 6.487 in (164.77 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 6.693 in (170 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

It resists petroleum-based oils, greases and lubricants, and propane and butane. 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).

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

This item is sold individually under part number HB90165. Unit weight is approximately 1.871 g and nominal inside diameter is listed as 6 1/2 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.