8-354 BLACK BUNA 90D BACK-UP RING

Buna-N Back-Up Ring, 5.1 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
354
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
5 1/8 inch
Nominal Outside Diameter
5 1/2 inch
Unit of Measure
EA
SKU:
HB90354
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Product Specification

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This back-up ring is supplied in AS568-354 black Buna-N (Nitrile) 90 Shore A supplied with an inside diameter of 5.1 in (129.54 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.52 in (140.21 mm), catalogued under part number HB90354. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

Buna-N (Nitrile) delivers reliable performance in both static and dynamic service, an economical choice for high-volume maintenance programs. The material holds up against greases and lubricants, petroleum-based oils, and hydraulic fluids. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving ozone and direct sunlight or ketones call for a different compound.

Common environments for this compound include hydraulic and pneumatic systems, fluid power, and automotive.

HB90354 ships individually. Unit weight is approximately 4.139 g. As always, verify media compatibility and operating conditions against the requirements of your specific application. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Item
HB90354
Description
8-354 BLACK BUNA 90D BACK-UP RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
5.1 inch (129.54 mm)
Actual Outside Diameter
5.52 inch (140.21 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings