This back-up ring is supplied in AS568-395 black Buna-N (Nitrile) 90 Shore A measuring an inside diameter of 25.94 in (658.88 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 26.36 in (669.54 mm), catalogued under part number HB90395. It allows a standard o-ring to operate at higher pressures than it could unsupported.
As a material, Buna-N (Nitrile) delivers an economical choice for high-volume maintenance programs and low compression set under sustained load. It resists many alcohols, water, and propane and butane. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Exposure to strong acids or ketones will shorten service life.
Typical settings include fluid power, agricultural equipment, and automotive.
This item is sold individually under part number HB90395. Nominal inside diameter is listed as 26 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description 8-395 BLACK BUNA 90D BACK-UP RING
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 25.94 inch (658.88 mm)
Actual_OD 26.36 inch (669.54 mm)
ProductCode Description O-Rings - Backup Rings