8-106 BLACK BUNA 90D BACK-UP RING

HB90106 is an AS568-106 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 0.174 in (4.42 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 0.38 in (9.65 mm). In service, this back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

Expect good resistance to hydraulic fluids, many alcohols, and propane and butane. That behavior comes from the compound itself: Buna-N (Nitrile) is known for strong abrasion and tear resistance, low compression set under sustained load. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with ketones or ozone and direct sunlight.

Typical settings include automotive, agricultural equipment, and hydraulic and pneumatic systems.

HB90106 ships individually. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.