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568-421 HSN90 DURO ORINGS

HNBR O-Ring, 3.975 in ID x 0.275 CS, 90A, Green, -40 to 325°F

Status
Out of Stock
Est. Ship Date
21 Oct 2026
Material
HNBR
Dash Size
421
Durometer
90 Shore A
Cross Section Type
Round
Color
Green
Minimum Temperature
-40°F (-40°C)
Maximum Temperature
325°F (163°C)
Nominal Cross Section
1/4 inch
Nominal Inside Diameter
4 inch
Nominal Outside Diameter
4 1/2 inch
Unit of Measure
EA
SKU:
HSN90421

Product Specification

-
APG stocks the HSN90421, an AS568-421 green HNBR (Hydrogenated Nitrile) 90 Shore A O-Ring built to an inside diameter of 3.975 in (100.97 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 4.525 in (114.94 mm). An o-ring remains the most cost-effective sealing element available for pressurized assemblies.

As a material, HNBR (Hydrogenated Nitrile) is valued for excellent abrasion and tear strength, strong resistance to rapid gas decompression. It resists petroleum oils and fuels, modern refrigerants, and ozone and weathering. Continuous operating temperature is published at -40°F (-40°C) to 325°F (162.8°C). Exposure to ketones or chlorinated hydrocarbons will shorten service life.

Typical settings include commercial refrigeration, heavy-duty powertrain, and automotive air conditioning.

Order part number HSN90421, sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Item
HSN90421
Description
568-421 HSN90 DURO ORINGS
Actual Cross Section
0.275 inch (6.99 mm)
Actual Inside Diameter
3.975 inch (100.97 mm)
Actual Outside Diameter
4.525 inch (114.94 mm)
FDA Compliant
No
Measurement System
Imperial
Metal Detectable
No
NSF Certified
No
Product Code
6006
Product Category
O-Rings - Bulk - Premium