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-390 BLACK BUNA 70D O-RING

Buna-N O-Ring, 20.953 in ID x 0.21 CS, 70A, Black, Metal Det., -40 to 250°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
Buna-N (Nitrile / NBR)
Dash Size
390
Durometer
70 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
21 inch
Nominal Outside Diameter
21 3/8 inch
Unit of Measure
EA
SKU:
H70MD390

Product Specification

-
Ordered as H70MD390, this is an AS568-390 black Buna-N (Nitrile) 70 Shore A O-Ring built to an inside diameter of 20.953 in (532.21 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 21.373 in (542.87 mm). The o-ring delivers dependable bidirectional sealing in a compact groove envelope.

It resists hydraulic fluids, water, and petroleum-based oils. That behavior comes from the compound itself: Buna-N (Nitrile) is valued for reliable performance in both static and dynamic service, low compression set under sustained load. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. It should not be specified for service in ketones or automotive brake fluid.

This item is metal detectable for HACCP and foreign-body control programs. Common environments for this compound include fluid power, general industrial maintenance, and hydraulic and pneumatic systems.

This item is sold individually under part number H70MD390. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
Item
H70MD390
Description
-390 BLACK BUNA 70D O-RING
Actual Cross Section
0.21 inch (5.33 mm)
Actual Inside Diameter
20.953 inch (532.21 mm)
Actual Outside Diameter
21.373 inch (542.87 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
Yes
NSF Certified
No
Product Code
6012
Product Category
O-Rings - FDA / Metal Detectable