AS568-431 Buna-N 90 Duro Black O-Ring for 5-1/4 ID X 1/4 CS

Buna-N O-Rings 90 Duro Black BN900100-431

$ 2.08 per Each

Minimum Order Quantity (MOQ): 15

Ships within 14 days

Qty	Price
15 - 16	$2.0800
17 - 36	$1.5600
37 - 72	$1.2480
73 - 144	$0.9360
145+	$0.7806

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Product Details

Material	Buna-N
Temperature Range	-40°F to 250°F
Cross Sectional Shape	Round
Hardness	90
Dash	431
Fractional	ID: 5-1/4 CS: 1/4 OD: 5-3/4
Actual (Inch)	ID: 5.225 ± 0.037 CS: 0.275 ± 0.006 OD: 5.775
Actual (Metric)	ID: 132.72 ± 0.94 CS: 6.99 ± 0.15 OD: 146.700

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.