8-234 BLACK BUNA 90D BACK-UP RING

The HB90234 is an AS568-234 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 2.984 in (75.79 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 3.262 in (82.85 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Expect good resistance to hydraulic fluids, greases and lubricants, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for reliable performance in both static and dynamic service, an economical choice for high-volume maintenance programs. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Exposure to ozone and direct sunlight or automotive brake fluid will shorten service life.

Typical settings include general industrial maintenance, automotive, and fluid power.

Reference part number HB90234 when ordering; the item is sold individually. Unit weight is approximately 1.1395 g and nominal inside diameter is listed as 3 inch. Review your operating media and conditions against this specification before installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.