The HB90465 is an AS568-465 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 17.955 in (456.06 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 18.505 in (470.03 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
This material stands up to hydraulic fluids, greases and lubricants, and water. Buna-N (Nitrile) is known for low compression set under sustained load, reliable performance in both static and dynamic service. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C).
It sees regular use in fluid power, automotive, and agricultural equipment.
Reference part number HB90465 when ordering; the item is sold individually. Unit weight is approximately 31.1511 g and nominal inside diameter is listed as 18 inch. 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 8-465 BLACK BUNA 90D BACK-UP RING
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 17.955 inch (456.06 mm)
Actual Outside Diameter 18.505 inch (470.03 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings