8-216 BLACK BUNA 90D BACK-UP RING

Ordered as HB90216, this is an AS568-216 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 1.109 in (28.17 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.387 in (35.23 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Buna-N (Nitrile) is specified for an economical choice for high-volume maintenance programs and the most widely specified general-purpose sealing elastomer. Expect good resistance to hydraulic fluids, water, and many alcohols. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Exposure to automotive brake fluid or polar solvents will shorten service life.

Maintenance and OEM teams specify it across construction equipment, agricultural equipment, and fluid power.

Order part number HB90216, sold individually. Unit weight is approximately 0.4391 g and nominal inside diameter is listed as 1 1/8 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.