8-436 BLACK BUNA 90D BACK-UP RING

Buna-N Back-Up Ring, 5.85 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
436
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
5 7/8 inch
Nominal Outside Diameter
6 3/8 inch
Unit of Measure
EA
SKU:
HB90436
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Product Specification

-
This back-up ring is supplied in AS568-436 black Buna-N (Nitrile) 90 Shore A measuring an inside diameter of 5.85 in (148.59 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 6.4 in (162.56 mm), catalogued under part number HB90436. It bridges the extrusion gap so the primary seal holds its shape under load.

Buna-N (Nitrile) is specified here for low compression set under sustained load and economical choice for high-volume maintenance programs. Expect good resistance to propane and butane, greases and lubricants, and petroleum-based oils. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with polar solvents or ketones.

Common environments for this compound include general industrial maintenance, construction equipment, and agricultural equipment.

Stocked as HB90436 and sold individually. Unit weight is approximately 10.429 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Item
HB90436
Description
8-436 BLACK BUNA 90D BACK-UP RING
Actual Cross Section
0.275 inch (6.99 mm)
Actual Inside Diameter
5.85 inch (148.59 mm)
Actual Outside Diameter
6.4 inch (162.56 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6002
Product Category
O-Rings - Backup Rings