8-451 BLACK BUNA 90D BACK-UP RING

Buna-N Back-Up Ring, 10.975 in ID x 0.275 CS, 90A, Black, -40 to 250°F

Status
Available
Est. Ship Date
31 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
451
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
1/4 inch
Nominal Inside Diameter
11 inch
Nominal Outside Diameter
11 1/2 inch
Unit of Measure
EA
SKU:
HB90451
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Product Specification

-
This back-up ring is supplied in AS568-451 black Buna-N (Nitrile) 90 Shore A supplied with an inside diameter of 10.975 in (278.77 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 11.525 in (292.74 mm), catalogued under part number HB90451. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

Buna-N (Nitrile) is specified for strong abrasion and tear resistance, the most widely specified general-purpose sealing elastomer. The material holds up against hydraulic fluids, petroleum-based oils, and water. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C).

It sees regular use in fluid power, hydraulic and pneumatic systems, and automotive.

Order part number HB90451, sold individually. Unit weight is approximately 19.4078 g and nominal inside diameter is listed as 11 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Item
HB90451
Description
8-451 BLACK BUNA 90D BACK-UP RING
Actual Cross Section
0.275 inch (6.99 mm)
Actual Inside Diameter
10.975 inch (278.77 mm)
Actual Outside Diameter
11.525 inch (292.74 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings