2-221 AS568 Oring Cad 2-221 AS568 Oring
2-221 AS568
AS568-221 Buna-N 70 Duro Black O-Ring for 1-7-16 ID X 1/8 CS

Buna-N O-Rings 70 Duro Black BN700100-221

$ 0.1969 per Each
Minimum Order Quantity (MOQ): 153
Ships within 7 days
Qty Price
153 - 177 $0.1969
178 - 380 $0.1477
381 - 761 $0.1181
762 - 1523 $0.0886
1524 - 3047 $0.0689
3048+ $0.0591

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 70
Dash 221
Fractional
  • ID: 1-7-16
  • CS: 1/8
  • OD: 1-11/16
Actual (Inch)
  • ID: 1.421 ± 0.012
  • CS: 0.139 ± 0.004
  • OD: 1.699
Actual (Metric)
  • ID: 36.09 ± 0.30
  • CS: 3.53 ± 0.10
  • OD: 43.150

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.