8-175 BLACK BUNA 90D BACK-UP RING

Buna-N Back-Up Ring, 8.987 in ID x 0.103 CS, 90A, Black, -40 to 250°F

Status
Out of Stock
Est. Ship Date
29 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
175
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
3/32 inch
Nominal Inside Diameter
9 inch
Nominal Outside Diameter
9 3/16 inch
Unit of Measure
EA
SKU:
HB90175

Product Specification

-
HB90175 is an AS568-175 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 8.987 in (228.27 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 9.193 in (233.5 mm). In service, this back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Expect good resistance to petroleum-based oils, greases and lubricants, and water. That behavior comes from the compound itself: Buna-N (Nitrile) is widely chosen for strong abrasion and tear resistance, reliable performance in both static and dynamic service. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in strong acids or ketones.

Typical settings include general industrial maintenance, automotive, and hydraulic and pneumatic systems.

Order part number HB90175, sold individually. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Item
HB90175
Description
8-175 BLACK BUNA 90D BACK-UP RING
Actual Cross Section
0.103 inch (2.62 mm)
Actual Inside Diameter
8.987 inch (228.27 mm)
Actual Outside Diameter
9.193 inch (233.5 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings