8-248 BLACK BUNA 90D BACK-UP RING

Part number HB90248 is an AS568-248 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 4.734 in (120.24 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.012 in (127.3 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Expect good resistance to many alcohols, water, and hydraulic fluids. Buna-N (Nitrile) delivers strong abrasion and tear resistance, an economical choice for high-volume maintenance programs. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving polar solvents or automotive brake fluid call for a different compound.

You will find this material specified across construction equipment, automotive, and agricultural equipment.

Stocked as HB90248 and sold individually. Unit weight is approximately 1.7148 g and nominal inside diameter is listed as 4 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.