Buna-N O-Rings (NBR Nitrile) Selection Guide

Buna-N O-Rings
Buna-N O-Rings

Buna-N o-rings also referred to as NBR o-rings and Nitrile o-rings are the most widely used o-ring material in the word because of low cost, good mechanical performance with resistance to water, most basic oils, lubricants and some fuels, many pneumatic, hydraulic systems, and the default choice for basic applications. Buna-N o-rings are not recommended for exposure to sunlight, UV light, ozone and general outdoor weathering or hash chemicals, acids, keytones and many others.

Custom size Buna-N o-rings can typically be supplied without additional tooling fees within a few weeks. As the world’s largest o-ring inventory network, Marco Rubber’s direct purchasing power can deliver substantial savings on Buna-N o-rings. Order Buna-N o-rings online today!

Recommended Use Not Recommended For Mechanical Properties
Silicone Greases / Oils
Petroleum Oils / Fuels
Ethylene Glycol Fluids
Ketones (MEK)
Halogenated Hydrocarbons
Auto / Aircraft Brake Fluids
Strong Acids
Sunlight, Ozone,  Weathering
Good Wear Resistance
Good Compression Set Resistance
Good Short-Term Resilience
Good Permeation Resistance

Buna-N Compatibility and Order NBR Orings Online In Stock for Low Cost Oil Resistance

Hundreds more specialty compounds available. Contact a Marco Sales Consultant or Engineer for more information.

Marco Compound Number Datasheet Hardness
(Shore A)
Color Low Temp.
°F (°C)
High Temp.
°F (°C)


B1000 70 Black -31 (-35) 250 (121) Lowest cost highest inventory general purpose commodity NBR compound. Compare to Parker N1470-70 and N0674-70 and Parco 4200-70 and 4900-70. Available in nearly any color and hardness.
B1001 90 Black -31 (-35) 250 (121) General purpose, higher pressure applications. Compare to Parker N0552-90 and N1490-90 and Parco 4200-90 and 4900-90.
B1002 70 Black -31 (-35) 250 (121) FDA compliant per 21 CFR 177.2600. Compare to Parker N0508-75 and N1069-70.
B1005 90 Black -31 (-35) 250 (121) FDA compliant, higher hardness.
B1006 50 Black -31 (-35) 250 (121) General purpose, lower hardness for lower closure force applications. FDA compliant and alternative colors available. Compare to Parker N0299-50.
B1010 80 Black -31 (-35) 225 (107) General purpose, higher hardness. Compare to Parker N0368-80.
B1011 70 Black -31 (-35) 230 (110) Internally lubricated with PTFE to reduce friction. Silicone oil and Moly (MOS2) internal lubricants available. Alternative hardness and colors also available.
B1017 70 Black -35 (-37) 250 (121) UL 157 listed for several approved uses.
B1058 70 Black -31 (-35) 250 (121) NSF 61 certified for drinking water applications.
B1063 95 Black -31 (-35) 250 (121) Very high hardness for extreme pressure applications.
B1083 70 Black -65 (-54) 275 (135) Improved lower and higher temperature resistance and improved oil resistance at higher temperature. Compare to Parker N0794-75 and M83461 and Parco 4367-70.
B1105 70 Black -31 (-35) 250 (121) Metal detectable for contamination detection sensors. FDA compliant per 21 CFR 177.2600. Formulated for food contact and life science applications. Additional colors available.
B1122 70 Black -31 (-35) 250 (121) NSF 51 certified for food contact.
M1000 70 Black -65 (-54) 275 (135) Mil Spec (Military specification) AMS-P-25732, MS28775-### per MIL-P-25732C-(1).
M1001 75 Black -65 (-54) 275 (135) Mil Spec (Military specification) AMS-P-83461, M83461/1-### per MIL-P-83461B#3. Improved low temperature resistance and hydraulic fluid resistance.
M1002 65 Black -65 (-54) 250 (121) Mil Spec (Military specification) MS29513-###, MS29512-##, AMS-P-5315B.
M1004 90 Black -65 (-54) 275 (135) Mil Spec (Military specification) MS28778, AMS-P-5510C.
M1005 65 Black -70 (-57) 200 (94) Mil Spec (Military specification) AMS7271, AS3578.

Common Names:

Buna-N, Nitrile, NBR, Acrylonitrile Butadiene Rubber

Trade Names:


Buna-N O-Rings Temperature Range

The temperature ranges presented above are approximations for dry air service only and should not be used to determine design specifications or end-use temperature limits. Actual temperature range of a compound in an end-use application is highly dependent on part type, hardware configuration, applied forces, chemical media, pressure and thermal cycling effects, and other factors. The most practical way of determining an end-use temperature range is testing in the actual application conditions. Consult a Marco Engineer for more details.

Buna-N O-Rings Typical Applications and Products:

The range of performance characteristics of Buna-N allows it to be utilized in a diverse set of applications. NBR is often used for gaskets and o-rings in pneumatic, hydraulic, and fuel systems. V-packings and backup rings made from high-hardness Nitrile compounds are common in high pressure environments in the Oil and Gas industry. The abrasion and wear resistance of NBR make it useful for dynamic oil seals for rotary and reciprocating shafts. NBR is relatively easy to process which keeps costs down for custom extrusions and complex molds. Hardness ranges from 40 Shore A to 90 Shore A. Hydrogenated versions of NBR (HNBR) have enhanced mechanical properties as well as greater thermal and chemical stability. Specific physical properties and chemical resistances vary by compound formulation.

NBR can be compounded for enhanced oil and fuel resistance, increased temperature flexibility, high hardness and extrusion resistance, low compression set, and a variety of other attributes. The physical properties of the compound largely depend on the Acrylonitrile content of the formulation. For example, high Acrylonitrile content causes increased oil and fuel resistance while adversely affecting low temperature flexibility and compression set resistance. It is important to consider the offsetting attributes when selecting an NBR formulation. Please contact a Marco Rubber engineer for assistance finding the best compound for your application.

Buna-N O-Rings Chemical Compatibility and Resistance:

  • Petroleum greases, mineral oils, vegetable oils
  • Aliphatic hydrocarbons
  • Hydraulic fluids (HFA, HFB, HFC types)
  • Limited resistance to dilute acids, alkalis, and solvents

Buna-N O-Rings Not Compatible With:

  • Highly Aromatic fuels and hydrocarbons
  • Weathering, sunlight and ozone
  • Chlorinated hydrocarbons
  • Polar solvents
  • Glycol brake fluids

Buna-N O-Rings Compound and Product Options:

Not a complete list of offerings. Please contact a Marco Sales Consultant or Engineer to discuss additional options. See Popular Compounds list below for compound examples.

  • Internal Lubrication with PTFE and others
  • High strength
  • Flame resistant
  • ABS compatible
  • Anti-Static
  • WRAS, KTW and NSF Compliant
  • FDA compliant
  • Metal and X-ray detectable
  • Gamma Radiation Resistance
  • Tight and/or specific tolerances
  • Specific AQL Inspection requirement
  • Surface free of silicone oil
  • PTFE coated in choice color
  • Special tumbling for complete flash removal
  • Talcum powder on surface to reduce sticking
  • Specific packaging requirements
  • Special bag and Label requirements
  • Variety of colors available

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