AS568-340 Buna-N 70 Duro Black O-Ring for 3-3/8 ID X 3/16 CS

Buna-N O-Rings 70 Duro Black BN700100-340

$ 0.6768 per Each

Minimum Order Quantity (MOQ): 45

Ships within 7 days

Qty	Price
45 - 51	$0.6768
52 - 110	$0.5076
111 - 221	$0.4061
222 - 443	$0.3046
444 - 886	$0.2369
887+	$0.2200

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Product Details

Material	Buna-N
Temperature Range	-40°F to 250°F
Cross Sectional Shape	Round
Hardness	70
Dash	340
Fractional	ID: 3-3/8 CS: 3/16 OD: 3-3/4
Actual (Inch)	ID: 3.350 ± 0.024 CS: 0.210 ± 0.005 OD: 3.770
Actual (Metric)	ID: 85.09 ± 0.61 CS: 5.33 ± 0.13 OD: 95.750

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.