Ordered as HB90104, this is an AS568-104 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 0.112 in (2.84 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 0.318 in (8.08 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
Buna-N (Nitrile) is specified here for economical choice for high-volume maintenance programs, reliable performance in both static and dynamic service. The material holds up against petroleum-based oils, propane and butane, and hydraulic fluids. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving automotive brake fluid or polar solvents call for a different compound.
Common environments for this compound include agricultural equipment, fluid power, and general industrial maintenance.
Order part number HB90104, sold individually. Unit weight is approximately 0.1114 g. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
description 8-104 BLACK BUNA 90D BACK-UP RING
Actual_CS 0.103 inch (2.62 mm)
Actual_ID 0.112 inch (2.84 mm)
Actual_OD 0.318 inch (8.08 mm)
ProductCode Description O-Rings - Backup Rings