2-904 AS568 Oring Cad 2-904 AS568 Oring
2-904 AS568
AS568-904 Buna-N 90 Duro Black O-Ring for ID X CS

Buna-N O-Rings 90 Duro Black BN900100-904

$ 0.042 per Each
Minimum Order Quantity (MOQ): 715
Ships within 14 days
Qty Price
715 - 833 $0.0420
834 - 1785 $0.0315
1786 - 3571 $0.0252
3572 - 7142 $0.0189
7143 - 14285 $0.0147
14286+ $0.0126

Ordering in large quantities? Ask for a lead time quote — we'll get back to you with pricing and lead time.

Product Details
Material Buna-N
Temperature Range -40°F to 250°F
Cross Sectional Shape Round
Hardness 90
Dash 904
Actual (Inch)
  • ID: 0.351 ± 0.005
  • CS: 0.072 ± 0.003
  • OD: 0.495
Actual (Metric)
  • ID: 8.92 ± 0.13
  • CS: 1.83 ± 0.08
  • OD: 12.580

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.