8-360 BLACK BUNA 90D BACK-UP RING

Buna-N Back-Up Ring, 5.85 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
360
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 7/8 inch
Nominal Outside Diameter
6 1/4 inch
Unit of Measure
EA
SKU:
HB90360
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Product Specification

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HB90360 is an AS568-360 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 5.85 in (148.59 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 6.27 in (159.26 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

Buna-N (Nitrile) delivers an economical choice for high-volume maintenance programs, reliable performance in both static and dynamic service. The material holds up against greases and lubricants, water, and petroleum-based oils. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with strong acids or ketones.

It sees regular use in general industrial maintenance, hydraulic and pneumatic systems, and construction equipment.

Reference part number HB90360 when ordering; the item is sold individually. Unit weight is approximately 5.036 g and nominal inside diameter is listed as 5 7/8 inch. Check the compound against your process media, pressure and temperature before committing to a design. For a size or compound outside the standard catalog, APG can quote from a print or sample.
Item
HB90360
Description
8-360 BLACK BUNA 90D BACK-UP RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
5.85 inch (148.59 mm)
Actual Outside Diameter
6.27 inch (159.26 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings