8-118 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90118, an AS568-118 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 0.862 in (21.89 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.068 in (27.13 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Buna-N (Nitrile) is specified here for reliable performance in both static and dynamic service, economical choice for high-volume maintenance programs. It resists propane and butane, many alcohols, and hydraulic fluids. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C).

It sees regular use in automotive, hydraulic and pneumatic systems, and agricultural equipment.

This item is sold individually under part number HB90118. Unit weight is approximately 0.2699 g and nominal inside diameter is listed as 7/8 inch. Review your operating media and conditions against this specification before installation. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.