AS568-010 B50 (NBR) Buna-N Nitrile 50 Duro O-Ring

1/4"ID X 3/8"OD X 1/16"CS

Buna-N O-Rings 50 Duro Extra-Soft (NBR):

The AS568-010 B50 Nitrile O-Ring is a 50 Shore A durometer, extra-soft Buna-N (NBR) seal ideal for low-pressure applications where excellent conformability and leak-free sealing are critical. Its softer compound delivers a tighter, more compliant seal against irregular or delicate mating surfaces — a key advantage over standard 70 Duro rings in light-load static gasket and face seal designs.

Nitrile (Buna-N / NBR) is the most widely used elastomer in sealing applications worldwide, valued for its outstanding resistance to petroleum-based oils, fuels, and hydraulic fluids. This 50 Duro formulation retains all the chemical compatibility strengths of standard NBR while offering enhanced flexibility and lower compression force requirements.

Buna-N / Nitrile 50 Duro Recommended Uses:

• General purpose static sealing and gasket applications
• Petroleum oils, fuels, and lubricants
• Hydraulic fluids (mineral oil-based)
• Gasoline and diesel fuel systems
• L.P. (propane/butane) gas systems
• Cold water and low-pressure plumbing
• Silicone greases and oils
• Di-ester base lubricants (MIL-L-7808)
• Ethylene glycol-based fluids (Hydrolubes)
• Low-load face seals and soft-surface sealing applications

Not Recommended For:

• Halogenated hydrocarbons (carbon tetrachloride, trichloroethylene)
• Nitro hydrocarbons (nitrobenzene, aniline)
• Phosphate ester hydraulic fluids (Skydrol, Fyrquel, Pydraul)
• Ketones (MEK, acetone)
• Ozone, UV, sunlight, or prolonged outdoor weathering exposure
• Strong acids
• Automotive brake fluid

Compound Info:

• Material: General purpose, sulfur-cured Nitrile (Buna-N / NBR)
• Color: Black
• Durometer: 50 Shore A (Extra-Soft)
• FDA Compliant: No
• ASTM D2000-99 Grade: M2BG507 A14 B14 EA14 EO34 F17Y

Operating Temperature: -40°F to +250°F (-40°C to +121°C)