8-281 BLACK BUNA 90D BACK-UP RING

Buna-N Back-Up Ring, 14.984 in ID x 0.139 CS, 90A, Black, -40 to 250°F

Status
Available
Est. Ship Date
31 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
281
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
1/8 inch
Nominal Inside Diameter
15 inch
Nominal Outside Diameter
15 1/4 inch
Unit of Measure
EA
SKU:
HB90281
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Product Specification

-
The HB90281 is an AS568-281 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 14.984 in (380.59 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 15.262 in (387.65 mm). This back-up ring 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, reliable performance in both static and dynamic service. It resists many alcohols, greases and lubricants, and petroleum-based oils. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where ozone and direct sunlight or polar solvents are present.

It sees regular use in agricultural equipment, construction equipment, and general industrial maintenance.

HB90281 ships individually. Unit weight is approximately 5.531 g and nominal inside diameter is listed as 15 inch. Check the compound against your process media, pressure and temperature before committing to a design. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
Item
HB90281
Description
8-281 BLACK BUNA 90D BACK-UP RING
Actual Cross Section
0.139 inch (3.53 mm)
Actual Inside Diameter
14.984 inch (380.59 mm)
Actual Outside Diameter
15.262 inch (387.65 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings