AS568-257 Buna-N 70 Duro Black O-Ring for 5-7/8 ID X 1/8 CS

Buna-N O-Rings 70 Duro Black BN700100-257

$ 0.852 per Each

Minimum Order Quantity (MOQ): 36

Ships within 7 days

Qty	Price
36 - 41	$0.8520
42 - 88	$0.6390
89 - 176	$0.5112
177 - 352	$0.3834
353+	$0.3131

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Product Details

Material	Buna-N
Temperature Range	-40°F to 250°F
Cross Sectional Shape	Round
Hardness	70
Dash	257
Fractional	ID: 5-7/8 CS: 1/8 OD: 6-1/8
Actual (Inch)	ID: 5.859 ± 0.035 CS: 0.139 ± 0.004 OD: 6.137
Actual (Metric)	ID: 148.82 ± 0.89 CS: 3.53 ± 0.10 OD: 155.880

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.