This back-up ring is supplied in AS568-159 black Buna-N (Nitrile) 90 Shore A measuring an inside diameter of 4.987 in (126.67 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 5.193 in (131.9 mm), catalogued under part number HB90159. It extends o-ring service life by supporting the seal against extrusion under high pressure.
It resists petroleum-based oils, greases and lubricants, and hydraulic fluids. Buna-N (Nitrile) offers strong abrasion and tear resistance, the most widely specified general-purpose sealing elastomer. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where ketones or strong acids are present.
You will find this material specified across construction equipment, fluid power, and automotive.
Order part number HB90159, sold individually. Unit weight is approximately 1.451 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Description 8-159 BLACK BUNA 90D BACK-UP RING
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 4.987 inch (126.67 mm)
Actual Outside Diameter 5.193 inch (131.9 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings