2-309 AS568 Oring Cad 2-309 AS568 Oring
2-309 AS568
AS568-309 Buna-N 70 Duro Black FDA O-Ring for 7/16 ID X 3/16 CS

Buna-N O-Rings 70 Duro Black FDA BN700101-309

$ 0.199 per Each
Minimum Order Quantity (MOQ): 151
Ships within 10 days
Qty Price
151 - 175 $0.1990
176 - 376 $0.1492
377 - 753 $0.1194
754 - 1507 $0.0895
1508 - 3015 $0.0697
3016+ $0.0597

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 309
Fractional
  • ID: 7/16
  • CS: 3/16
  • OD: 13/16
Actual (Inch)
  • ID: 0.412 ± 0.005
  • CS: 0.210 ± 0.005
  • OD: 0.832
Actual (Metric)
  • ID: 10.46 ± 0.13
  • CS: 5.33 ± 0.13
  • OD: 21.120

FDA-approved Buna-N (Nitrile) O-rings are made from a synthetic rubber copolymer of acrylonitrile (ACN) and butadiene, specially formulated to meet the Food and Drug Administration (FDA) requirements for food contact applications. These O-rings offer excellent resistance to oils, fuels, and many chemicals while being compliant with FDA regulations for safe use in food processing, pharmaceutical, and medical industries. FDA Buna-N O-rings provide high mechanical strength, outstanding wear resistance, and good tensile strength, making them ideal for sanitary applications.

FDA Buna-N Recommended Uses

Seals and gaskets for food and beverage processing, pharmaceutical applications, medical devices, sanitary sealing applications, food handling equipment, and laboratory applications.

FDA Buna-N Not Recommended

Brake fluid, ozone, UV exposure, phosphate esters, chlorinated hydrocarbons, aromatic hydrocarbons, ketones, strong acids, atmospheric aging.

FDA Buna-N Limitations

  • Not suitable for ozone, sunlight, or weathering exposure.
  • Limited performance in high-temperature environments.
  • Not ideal for strong acids and alkalis.
  • Not recommended for applications requiring low compression set.
FDA Buna-N Usable Temperature Range

-30 to 250°F (-34 to 121°C)

FDA Buna-N Also Known As

FDA Buna-N, Nitrile, NBR, Nitrile Butadiene Rubber (FDA Compliant).