Carbon Graphite Grade Selection Guide
A downloadable PDF of our selection guide
Carbon Graphite Grade Selection Guide
ROC Carbon carbon/graphite materials combine the superior strength, hardness, and wear resistance of carbon with the natural lubricity of graphite. These chemically bonded carbon materials are strong and thermally stable and are inert in most chemical and corrosive applications. When even higher mechanical properties or impervious materials are required, material performance properties can be enhanced by special impregnation with resins or metals. These impregnated carbon grades offer maximum resistance to corrosion, wear, and oxidation.
The grades presented in the guide are only a representative sampling of our many grades. Please call for information on other grades.
In general, ROC Carbon carbon/graphite seals and beaings are used where extreme operating temperatures and/or corrosive fluids would cause conventional lubricants to decompose, where lubricants would contaminate process fluids, and where equipment design make conventional lubricating systems too expensive to install and maintain. Other applications for which ROC Carbon supplies carbon/ graphite materials include electrodes and brazing boats, jigs, and fixtures.
Using This Guide
Look up the chemical/environment for your application in Table 2 and determine the CR (Corrosion Resistance) Group.
Using Table 1, find the materials(s) that match the CR Group found in step 1.
Verify the operation temperature does not exceed temperature limit of the material. Remember to consider heat generation in the bearing or seal can cause higher temperatures in the materials.
Our Technical Support Group would be happy to assist you in:
- Material selection
- Bearing loads
- Press fits and recommended clearances
Physical Properties of selected grades
| CR Group | Grade | Composition Code1 | Apparent Density | Hardness | Flexural Strength (PSI) | Flexural Strength (MPa) | Compressive Strength (PSI) | Compressive Strength (MPa) | Modulus of Elasticity | Coefficient of Thermal Expansion | Temperature Limit (°F) | Temperature Limit (°C) | Temperature Limit (°F) | Temperature Limit (°C) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | R-103 | G | (1.72 g/cc) | (45 Shore Scleroscope) | 4,200 | 29 | 9,600 | 66 | - | 1.5 | 750 | 399 | 5,000 | 2,760 |
| 1 | R-115 | G | (1.78 g/cc) | (76 Shore Scleroscope) | 9,425v | 65 | 19,575 | 135 | 1.7 | 3.1 | 850 | 454 | 5,000 | 2,760 |
| 1 | R-115 | G | (1,80 g/cc) | (60 Shore Scleroscope) | 7,850 | 54 | 14,800 | 102 | 1.5 | 2.7 | 800 | 427 | 5,000 | 2,760 |
| 1 | R-383 | G | (1.78 g/cc) | (55 Shore Scleroscope) | 6,000 | 41 | 12,100 | 83 | 1.2 | 2.6 | 800 | 427 | 5,000 | 2,760 |
| 1 | R-433 | CG | (1.72 g/cc) | (72 Shore Scleroscope) | 8,400 | 58 | 24,000 | 165 | 1.5 | 3.2 | 650 | 343 | 1,800 | 982 |
| 2 | R-122 | CGI | (1.82 g/cc) | (84 Shore Scleroscope) | 9,300 | 64 | 30,000 | 207 | 3.3 | 2.9 | 500 | 260 | 500 | 260 |
| 2 | R-143 | CGI | (1.86 g/cc) | (90 Shore Scleroscope) | 11,000 | 76 | 32,000 | 221 | 3.2 | 2.8 | 500 | 260 | 500 | 260 |
| 2 | R-208 | CGI | (1.82 g/cc) | (101 Shore Scleroscope) | 11,000 | 76 | 29,000 | 200 | 3.4 | 2.2 | 390 | 199 | 390 | 199 |
| 2 | R-211 | CGI | (1.87 g/cc) | (87 Shore Scleroscope) | 11,300 | 78 | 35,500 | 245 | 3.2 | 3.1 | 480 | 249 | 480 | 249 |
| 2 | R-307 | CGI | (1.85 g/cc) | (85 Shore Scleroscope) | 10,000 | 69 | 25,000 | 172 | 2.3 | 2.6 | 500 | 260 | 500 | 260 |
| 4 | R-422 | GX | (1.85 g/cc) | (55 Shore Scleroscope) | 5,500 | 38 | 14,000 | 97 | 1.2 | 2.1 | 1,200 | 649 | 1,600 | 871 |
| 5 | R-116 | CG (SB) | (2.30 g/cc) | (88 Shore Scleroscope) | 13,050 | 90 | 43,500 | 300 | 3.9 | 2.8 | 752 | 400 | 932 | 500 |
| 5 | R-190 | CG (CU) | (2.85 g/cc) | (40 Shore Scleroscope) | 7,500 | 52 | 16,000 | 110 | 2.8 | 2.0 | 700 | 371 | 1,700 | 927 |
| 5 | R-191 | CG (NICR) | (2.40 g/cc) | (55 Shore Scleroscope) | 7,500 | 52 | 23,000 | 159 | 2.8 | 1.4 | 700 | 371 | 1,700 | 927 |
| 5 | R-203 | CG (SB) | (2.3 g/cc) | (120 (2) Shore Scleroscope) | 12,500 | 86 | 37,500 | 259 | 4.4 | 2.2 | 660 | 349 | 1,000 | 538 |
| 5 | R-204 | CG (B) | (2.45 g/cc) | (55 Shore Scleroscope) | 4,800 | 33 | 23,500 | 162 | 2.9 | 1.9 | 400 | 204 | 400 | 204 |
| 5 | R-391 | CG (BR) | (2.55 g/cc) | (55 Shore Scleroscope) | 8,500 | 59 | 25,000 | 172 | 3.1 | 2.1 | 700 | 371 | 1,700 | 927 |
1COMPOSITION CODES
B – Babbitt
BR – Bronze
C – Carbon
CU – Copper
G – Graphite
I – Impregnation
NICR – Nickel chrome
X – Oxidation Impregnation
SB – Antimony
2HRB
Note: The physical properties of ROC Carbon grades may vary in relation to the molded part size and configuration; the above values are typical and should be considered only as a guide or reference.
Chemical Compatibility
The tables on this page present general grade recommendations for chemical service. However, a particular grade’s resistance to chemical attack can vary substantially according to temperature, concentration, and exposure time. Please consult with ROC Carbon’s applications engineering staff to determine the appropriate grade for your specific application.
Corrosion Resistance by Specific Chemical
- Compatible
- Questionable
- Not Recommended
- Scroll to see more
| CR GROUPS | 1 | 2 | 3 | 4 | 5 |
|---|
| CR GROUPS | 1 | 2 | 3 | 4 | 5 |
|---|
Chemical Compatibility
ROC Carbon offers a portfolio of PEEK thermoplastic grades that provide good chemical resistance and excellent physical properties for applications including bearings, seals and other parts. Material grades are available as finished parts per your specifications or as raw material blanks for machining.
RAW MATERIAL AVAILABILITY
Solid cylinders up to 20-inch diameter
GENERAL PROPERTIES
- Good chemical resistance to alkalis, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, greases, and oils
- Self-lubricating
- Thermal stability
- Contamination resistance
- Mechanical strength
PEEK MATERIAL PROPERTIES
| Grade | R-700 | R-710 | R-720 | R-721 | R-730 | R-740 |
|---|---|---|---|---|---|---|
| Filler | None | 15% PTFE | 15% glass | 30% glass | 30% carbon | 30% carbon/PTFE |
| Density, g/cc | 1.32 | 1.40 | 1.39 | 1.49 | 1.40 | 1.44 |
| Hardness, HRR | 126 | 124* | 124 | 124 | 124 | 124 |
| Tensile strength, psi | 14,500 | 11,000 | 17,800 | 24,500 | 32,700 | 19,000 |
| Shear strength, psi | 7,700 | N/A | N/A | 14,000 | 14,000 | N/A |
| Flexural strength, psi | 24,700 | 19,000 | 26,000 | 33,500 | 51,000 | 30,450 |
| Temperature limit, °F | 500 | 500 | 500 | 500 | 500 | 500 |
| Coefficient of friction** | 0.34 | 0.11 | N/A | N/A | 0.28 | 0.11 |
| Grade | R-700 | R-710 | R-720 | R-721 | R-730 | R-740 |
|---|---|---|---|---|---|---|
| Filler | None | 15% PTFE | 15% glass | 30% glass | 30% carbon | 30% carbon/PTFE |
| Density, g/cc | 1.32 | 1.40 | 1.39 | 1.49 | 1.40 | 1.44 |
| Hardness, HRR | 126 | 124* | 124 | 124 | 124 | 124 |
| Tensile strength, psi | 14,500 | 11,000 | 17,800 | 24,500 | 32,700 | 19,000 |
| Shear strength, psi | 7,700 | N/A | N/A | 14,000 | 14,000 | N/A |
| Flexural strength, psi | 24,700 | 19,000 | 26,000 | 33,500 | 51,000 | 30,450 |
| Temperature limit, °F | 500 | 500 | 500 | 500 | 500 | 500 |
| Coefficient of friction** | 0.34 | 0.11 | N/A | N/A | 0.28 | 0.11 |
Values given are typical properties, not guaranteed minimum values.
* Estimated value (actual Shore 88)
**Friction coefficients are measured under specific test conditions. Actual values will vary with different operating parameters.
ROCBON PTFE Composites
ROCBON 1000 series is a selection of highperformance, reinforced fluorocarbon resin composites that are unique in the plastic family and that possess exceptional properties:
- Chemical resistance
- Self-lubricating
- Thermal stability
- Moisture resorbant
- Contamination resistance
- Mechanical strength
- Electrical insulation
RAW MATERIALS TECHNICAL SUPPORT
GRADES AND APPLICATIONS
| 1007 | Virgin PTFE for packings, seals and bushings |
| 1051 | 25% fiberglass-filled grade for common seals and bushings |
| 1911 and 1921 | Carbon/graphite-filled grades for bearings, piston rings, rider rings and various seals. An excellent combination that provides good service life. 1911 has 25% fill, 1921 has 35% fill |
| 1521 | 50% stainless steel-filled grade for bearings and valve seat applications where high load and corrosion are primary concerns. |
| 1821 | Moly/bronze-filled grade for bearing and seal applications where high load strength is needed. 55% bronze, 5% moly filled |
| 1551 | Ceramic-filled grade for applications where high wear resistance is required. (25% mica) |
| 1621 | 35% carbon fiber-filled grade where high strength and high wear performance is sought; a high-performance composite grade. |
sizes
SOLID CYLINDER
1.5 in. to 6 in. diameter
12 in. long
TUBE
1.5 in. to 15.875 in. diameter
12 in. long
LARGER SIZES
Available upon request
ROCBON PTFE Composite Properties
Note: The physical properties of ROC CARBON grades may vary in relation to the molded part size, configuration and the application conditions.
The above values are typical and should be considered only as a guide or reference.
MD = Molded direction; CD = Cross direction