Carbon Graphite for Aerospace Applications
As one of the few companies worldwide to develop and mix carbon grades, St. Marys Carbon has established a favorable reputation among aerospace engineering companies. Most commonly, engineers require our specialty carbon graphite products graded for high altitudes, high temperatures, or extremely low temperatures.
It’s common for non-carbon materials to fail at high altitudes, high temperatures, and low temperatures, which is why the aerospace industry so often turns to our proprietary carbon graphite grades. More specifically, our mechanical seals are manufactured in a variety of grades to suit any aerospace application. On occasion, aerospace applications also make use of our carbon graphite bearings.
St. Marys Carbon supplies carbon graphite solutions for both commercial and government aerospace applications. As such, we are AS9100 certified, U.S. Government and military certified, and ITAR registered.
Part & Product Lead Times
St. Marys Carbon works closely with engineers to ensure lead times are always met, but it’s important to recognize what factors may influence the delivery of aerospace seals or bearings.
Since St. Marys Carbon handles the creation of its seals and bearings from start to finish, each of our seals can be customized to meet specific industry needs. In the event that one of our base seal grades or bearings grades do not suffice, you may experience a longer lead time due to material development. In these instances, a member of our team will continually communicate the expected lead time to you as the project progresses.
Our spec sheets make it easy to deduce if our base grades are sufficient for your application. In the event that testing is preferred or required, the lead time will be adjusted accordingly. If you need assistance with testing, St. Marys Carbon is happy to help facilitate the tests.
Carbon Graphite Grade Testing
St. Marys Carbon’s top priority is ensuring our carbon graphite grades meet the needs of your application. For our base aerospace carbon graphite grades, you can find the value for any relevant properties on the product data sheets.
If you have any concerns about our base carbon graphite grades, we can provide a few samples for testing. If you prefer not to handle testing yourself, or you are unable to perform the tests, we can facilitate a third-party test on your behalf.
For aerospace applications that require custom carbon graphite solutions, testing will be necessary to ensure the parts are within tolerance.
Mechanical Seal Carbon Graphite Grades & Properties
| Grade | Density (lbs./ft. 3 ) |
Flexural Strength (psi) |
Compressive Strength (psi) |
Coefficient of Thermal Expansion (μ/°F) |
Temperature Limit Neutral (°F) |
Temperature Limit Oxidizing (°F) |
Scleroscope Hardness |
Applications |
| 49S | 112.94 | 8,400 | 23,000 | 2.49 | 500 | 500 | 75 | Mechanical Seals |
| 275 | 115.44 | 10,000 | 24,000 | 2.60 | 500 | 500 | 80 | Mechanical Seals |
| 416 | 115.50 | 13,000 | 33,000 | 2.80 | 500 | 500 | 95 | Mechanical Seals |
| 219 | 110.45 | 10,000 | 25,000 | 2.54 | 1,600 | 700 | 75 | Mechanical Seals |
| 375 | 118.56 | 10,000 | 25,000 | 2.60 | 500 | 500 | 80 | Mechanical Seals |
| 181S | 112.32 | 12,000 | 30,000 | 3.06 | 500 | 500 | 95 | Mechanical Seals |
Bearings Carbon Graphite Grades & Properties
| Grade | Density (lbs./ft. 3 ) |
Flexural Strength (psi) |
Compressive Strength (psi) |
Coefficient of Thermal Expansion (μ/°F) |
Temperature Limit Neutral (°F) |
Temperature Limit Oxidizing (°F) |
Scleroscope Hardness |
Applications |
| 181C | 111.07 | 10,000 | 30,000 | 3.06 | 500 | 500 | 90 | Bearings / Bushings |
| 75 | 106.08 | 8,100 | 21,500 | 2.80 | 3,000 | 750 | 80 | Bearings / Bushings |
| 75C | 112.32 | 9,300 | 30,000 | 3.25 | 500 | 500 | 95 | Bearings / Bushings |
| 416 | 115.50 | 13,000 | 33,000 | 2.80 | 500 | 500 | 95 | Bearings / Bushings |
| 35 | 109.20 | 7,000 | 17,500 | 2.40 | 5,000 | 850 | 60 | Bearings / Bushings |
| 35AH | 109.20 | 7,500 | 17,000 | 2.40 | 1,500 | 1,150 | 65 | Bearings / Bushings |
| 245 | 113.00 | 8,000 | 16,000 | 2.30 | 5,000 | 850 | 80 | Bearings / Bushings |
| 233 | 118.56 | 8,000 | 22,000 | 2.30 | 1,000 | 1,000 | 90 | Bearings / Bushings |
Custom Carbon Graphite Engineering Solutions
Although our base carbon graphite grades are ideal for the majority of aerospace applications, there are scenarios where custom carbon graphite grades are necessary. In these instances, we are not machining products to different specifications. Rather, we modify the base materials and physical properties of the carbon graphite to ensure it is perfect for your needs.
Since carbon graphite is a porous material, it can be impregnated with other materials to reduce porosity or to modify other characteristics of the material. Common accommodations include material strength, temperature limitations, friction level, corrosion resistance, and others.
If you require custom carbon graphite solutions for your aerospace applications, you’ll receive St. Marys Carbon’s total customer service throughout the entire process. From design to testing, our product development team will keep you informed.