8-325 BLACK BUNA 90D BACK-UP RING

Buna-N Back-Up Ring, 1.475 in ID x 0.21 CS, 90A, Black, -40 to 250°F

Status
Available
Est. Ship Date
31 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
325
Durometer
90 Shore A
Cross Section Type
Round
Color
Black
Minimum Temperature
-40°F (-40°C)
Maximum Temperature
250°F (121°C)
Nominal Cross Section
3/16 inch
Nominal Inside Diameter
1 1/2 inch
Nominal Outside Diameter
1 7/8 inch
Unit of Measure
EA
SKU:
HB90325
Please login to see price and add to cart

Product Specification

-
This back-up ring is supplied in AS568-325 black Buna-N (Nitrile) 90 Shore A with an inside diameter of 1.475 in (37.47 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.895 in (48.13 mm), catalogued under part number HB90325. It bridges the extrusion gap so the primary seal holds its shape under load.

As a material, Buna-N (Nitrile) is valued for the most widely specified general-purpose sealing elastomer and low compression set under sustained load. It resists hydraulic fluids, water, and many alcohols. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C).

You will find this material specified across hydraulic and pneumatic systems, general industrial maintenance, and construction equipment.

This item is sold individually under part number HB90325. Unit weight is approximately 1.4151 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Item
HB90325
Description
8-325 BLACK BUNA 90D BACK-UP RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
1.475 inch (37.47 mm)
Actual Outside Diameter
1.895 inch (48.13 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings