8-386 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90386, an AS568-386 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 16.955 in (430.66 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 17.375 in (441.33 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, Buna-N (Nitrile) is known for an economical choice for high-volume maintenance programs and the most widely specified general-purpose sealing elastomer. Expect good resistance to hydraulic fluids, petroleum-based oils, and propane and butane. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C).

Maintenance and OEM teams specify it across general industrial maintenance, fluid power, and agricultural equipment.

This item is sold individually under part number HB90386. Unit weight is approximately 14.181 g. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.