2-431 AS568 Oring Cad 2-431 AS568 Oring
2-431 AS568
AS568-431 Buna-N 70 Duro Black FDA O-Ring for 5-1/4 ID X 1/4 CS

Buna-N O-Rings 70 Duro Black FDA BN700101-431

$ 2.01 per Each
Minimum Order Quantity (MOQ): 15
Ships within 10 days
Qty Price
15 - 17 $2.0100
18 - 37 $1.5075
38 - 74 $1.2060
75 - 149 $0.9045
150+ $0.7524

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 431
Fractional
  • ID: 5-1/4
  • CS: 1/4
  • OD: 5-3/4
Actual (Inch)
  • ID: 5.225 ± 0.037
  • CS: 0.275 ± 0.006
  • OD: 5.775
Actual (Metric)
  • ID: 132.72 ± 0.94
  • CS: 6.99 ± 0.15
  • OD: 146.700

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).