APG stocks the HB90458, an AS568-458 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 14.475 in (367.67 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 15.025 in (381.64 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
Buna-N (Nitrile) is widely chosen for strong abrasion and tear resistance, low compression set under sustained load. This material stands up to many alcohols, hydraulic fluids, and propane and butane. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C).
It sees regular use in agricultural equipment, automotive, and fluid power.
This item is sold individually under part number HB90458. Unit weight is approximately 23.492 g. Check the compound against your process media, pressure and temperature before committing to a design. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Description 8-458 BLACK BUNA 90D BACK-UP RING
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 14.475 inch (367.67 mm)
Actual Outside Diameter 15.025 inch (381.64 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings