8-007 BLACK BUNA 90D BACK-UP RING

This back-up ring is supplied in AS568-007 black Buna-N (Nitrile) 90 Shore A supplied with an inside diameter of 0.145 in (3.68 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.285 in (7.24 mm), catalogued under part number HB90007. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

Buna-N (Nitrile) is known for strong abrasion and tear resistance, low compression set under sustained load. This material stands up to greases and lubricants, petroleum-based oils, and many alcohols. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Applications involving strong acids or automotive brake fluid call for a different compound.

Maintenance and OEM teams specify it across agricultural equipment, general industrial maintenance, and fluid power.

Stocked as HB90007 and sold individually. Unit weight is approximately 0.0423 g and nominal inside diameter is listed as 5/32 inch. Review your operating media and conditions against this specification before installation.