
O-Ring
Types Available
O-Rings are available in five different polymer materials as well as Gold and Platinum from Scientific Instrument Services. For a complete description of each of the types, select the type of material listed above.
O-Ring Dimension and Availability Charts
O-Rings are available in sizes (sizes 0, 1, 2 and 3) which correspond to the diameter of the cross section of the O-Ring. Within these groups the O-Rings are classified according to their inside diameter. In addition O-Ring Kits of the most popular sizes of O-Rings are available in both Buna and Viton®. If the size you require is not listed, it may still be available. Contact us with your requirements.
| Industry
Sizes |
Cross Section
Diameter (in.) |
Minimum Inside
Diameter (in.) |
Maximum Inside
Diameter (in.) |
| Size - 0 | 0.04 to 0.07 | 0.031 | 5.25 |
| Size - 1 | 1/16 (0.063) | 0.0625 | 9.75 |
| Size - 2 | 1/8 (0.125) | 0.1875 | 18 |
| Size - 3 | 3/16 (0.188) | 0.4375 | 11.5 |
Comparision of O Materials Used in the Construction of O-Rings
Each type has its advantages and disadvantages as listed in the chart below, and the type required depends on the O-Ring application. Of the various types of O-Rings available from SIS, Viton® is the most popular for mass spectrometers and other laboratory instruments. This is due to Viton®'s high temperature stability and good resistance to chemicals and ozone. Gold gaskets are used to make high vacuum and high temperature seals on vacuum flanges.
| Property | Buna-N | Viton® | Silicone | PTFE | Kalrez® |
|---|---|---|---|---|---|
| Part No. Prefix | B- | V- | S- | T- | K- |
| Tear Resistance | Good | Good | Poor | Excellent | Good |
| Abrasive Resistance | Good | Good | Poor | Excellent | Good |
| Ozone Resistance | Poor | Excellent | Excellent | Good | Excellent |
| Weather Resistance | Fair | Excellent | Excellent | Good | Excellent |
| Heat Resistance | Fair | Excellent | Excellent | Good | Excellent |
| Chemical Resistance | Fair | Excellent | Good | Excellent | Excellent |
| Oil Resistance | Poor | Excellent | Poor | Good | Excellent |
| Acid Resistance | Fair | Excellent | Good | Excellent | Excellent |
| Alkali Resistance | Good | Good | Fair | Excellent | Excellent |
| Steam Resistance | Fair | Fair | Poor | Good | Excellent |
| Minimum Usable Temp | -65 deg F
-54 deg C |
-65 deg F
-54 deg C |
-120 deg F
-85 Deg C |
-110 deg F
-79 deg C |
-35 deg F
-37 deg C |
| Maximum Usable Temp | 300 deg F
150 deg C |
500 deg F
260 deg C |
450 deg F
232 deg C |
500 deg F
260 deg C |
550 deg F
288 deg C |
| Color | Black | Black | Red | White | Black |
| Impermeability | Fair | Good | Poor | Excellent | Good |
| Tensile Strength | Good | Good | Poor | Excellent | Good |