Nitrile is the most widely used elastomer in the seal industry, and commonly used in o-ring and sealing applications. The popularity of nitrile is due to its excellent resistance to petroleum products and its ability to be compounded for service over a temperature range of -22°F to 212°F. Nitrile provides excellent compression set, tear, and abrasion resistance. The nitrile o-ring is commonly referred to as a Buna o-ring, or NBR o-rings. Columbia offers a complete selection of both the standard AS568 o-ring and metric o-ring sizes.
Nitrile
Chemical Resistance |
Very
Good |
Good |
Fair |
Poor |
| Aliphatic Hydrocarbons |
1 |
|
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| Alkali and salt solutions |
|
2 |
|
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| Aromatic Hydrocarbons |
|
|
|
4 |
| Brake Fluid Glycol Base |
|
|
|
4 |
| Brake Fluids Non-Petroleum |
|
|
|
4 |
| Chlorinated Hydrocarbons |
|
|
|
4 |
| Dilute acids |
|
2 |
|
|
| Hydraulic Fluids HFA, HFC, HFB |
1 |
|
|
|
| Polar Solvents (Ketones) |
|
|
|
4 |
| Silicone Fluids |
1 |
|
|
|
| Steam to 500ºF |
|
|
|
4 |
| Strong Acids |
|
|
|
4 |
| Water |
1 |
|
|
|
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*The nitrile o-ring compound attributes are used to outline the basic properties. Nitrile o-ring attributes can be adjusted by modifying the basic compound.
*Due to the number of interacting forces, it is STRONGLY RECOMMENDED THAT YOUR ELASTOMER SELECTION BE RIGOROUSLY TESTED IN THE ACTUAL APPLICATION, performance assumptions must be checked so that you are certain that all variables have been carefully considered.
| Chemical Description |
Acrylonitrile-butadiene rubber |
| Abbreviations (ASTM 1418) |
NBR |
| ISO / DIN |
NBR |
| Other Trade Names |
Buna-N |
| ASTM D2000 Designations |
BF, BG, BK, CH |
| Low Temperature Range |
-22°F / -30°C |
| High Temperature Range |
258°F / 100°C |
Nitrile
Physical Properties |
Very
Good |
Good |
Fair |
Poor |
| Abrasion Resistance |
|
2 |
|
|
| Acid Resistance |
|
|
3 |
|
| Chemical Resistance |
|
|
3 |
|
| Cold Resistance |
|
2 |
|
|
| Compression Set Resistance |
|
2 |
|
|
| Dynamic Properties |
|
2 |
|
|
| Electrical Properties |
|
|
3 |
|
| Elongation |
|
2 |
|
|
| Flame Resistance |
|
|
|
4 |
| Heat Resistance |
|
2 |
|
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| Impermeability |
|
2 |
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| Oil Resistance |
1 |
|
|
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| Ozone Resistance |
|
|
|
4 |
| Tear Resistance |
|
|
3 |
|
| Tensile Strength |
|
2 |
|
|
| Water Steam Resistance |
|
|
3 |
|
| Weather Resistance |
|
|
3 |
|
*The chemical compatibility and physical properties are listed as general characteristics of the nitrile o-ring compound. Speciality compounds can be derived to enhance or modify the performance to meet o-ring's application needs.
O-ring Measurement Chart
Nitrile O-rings can be made in custom sizes to fit any application specific needs. Our engineering staff can review your application and design a solution that satisfies those requirements. You can find assistance with o-ring gland design
here. You can find assistance with o-ring design
here. To request a quote on your o-ring specifications please submit a RFQ
here.
All stocked nitrile AS568 o-rings have three measurement types. First, a nominal inch reference, then actual inch sizes, and finally the metric size displayed in millimeters. Nitrile o-rings are stocked and cataloged by their AS568 number. This number references the Aerospace Standard 568 (AS 568) which was published by the SAE (Society of Automotive Engineers). Each o-ring is assigned a dash number which correlates directly to an exact o-ring size. You may view a complete chart of these o-ring sizes
here.
Nitrile O-rings are available in several metric sizes. Metric O-rings are cataloged by their cross section and inside diameter. Columbia references the metric nitrile o-rings by the compound number and the cross section along with the inside diameter. You may view a complete chart of the metric o-ring sizes
here.