8-038 BLACK BUNA 90D BACK-UP RING

HB90038 is an AS568-038 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 2.614 in (66.4 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 2.754 in (69.95 mm). In service, this back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Buna-N (Nitrile) is specified for strong abrasion and tear resistance, reliable performance in both static and dynamic service. Expect good resistance to petroleum-based oils, hydraulic fluids, and water. 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 ketones or automotive brake fluid are present.

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

Order part number HB90038, sold individually. Unit weight is approximately 0.4678 g and nominal inside diameter is listed as 2 5/8 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.