AS568-406 Buna-N 90 Duro Black O-Ring for 2-1/8 ID X 1/4 CS

Buna-N O-Rings 90 Duro Black BN900100-406

$ 1.01 per Each

Minimum Order Quantity (MOQ): 30

Ships within 14 days

Qty	Price
30 - 34	$1.0100
35 - 74	$0.7575
75 - 148	$0.6060
149 - 297	$0.4545
298+	$0.3686

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Product Details

Material	Buna-N
Temperature Range	-40°F to 250°F
Cross Sectional Shape	Round
Hardness	90
Dash	406
Fractional	ID: 2-1/8 CS: 1/4 OD: 2-5/8
Actual (Inch)	ID: 2.1 ± 0.018 CS: 0.275 ± 0.006 OD: 2.650
Actual (Metric)	ID: 53.34 ± 0.46 CS: 6.99 ± 0.15 OD: 67.320

Buna-N (Nitrile) O-rings are made from a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene. They are among the most widely used sealing materials due to their excellent resistance to oils, fuels, and many chemicals. Nitrile O-rings provide high mechanical strength, outstanding wear resistance, and good tensile strength, making them ideal for automotive, industrial, and aerospace applications.

Buna-N Recommended Uses

Seals and gaskets, fuel systems, hydraulic systems, oil and gas industry, automotive applications, general-purpose applications.

Buna-N Not Recommended

Brake fluid, ozone, UV exposure, phosphate esters, chlorinated hydrocarbons, aromatic hydrocarbons, ketones, strong acids, atmospheric aging.

Buna-N Limitations

Not suitable for ozone, sunlight, or weathering exposure.
Limited performance in high-temperature environmen.
Not ideal for strong acids and alkalis.
Not recommended for applications requiring low compression set.

Buna-N Usable Temperature Range

-30 to 250°F (-34 to 121°C)

Buna-N Also Known As

Buna-N, Nitrile, NBR, Nitrile Butadiene Rubber.