Frequently Asked Questions

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Carbon graphite is a combination of amorphous carbon and graphite, two allotropes of carbon. It is produced by mixing carbon binders and graphite fillers and baking the part at high heat. The result is a self-lubricating, homogeneous, solid carbon graphite material.

Carbon graphite contains both graphite and amorphous carbon whereas graphite contains no amorphous carbon. The amorphous carbon helps add strength to carbon graphite parts whereas graphite parts are softer and have better thermal properties. Contact the engineering department for help in determining which material composition is best for your application.

Carbon graphite is made by mixing together carbon binders and graphite fillers to create molded parts. These molded parts then go through a heating process where the binders carbonize. This results in a homogeneous combination of amorphous carbon and graphite–carbon graphite.

No, carbon graphite is self-lubricating due to the layered structure of graphite. As the carbon graphite part slides against a countersurface, layers of graphene (one layer in a graphite structure) are deposited onto the counter surface. This film provides lubrication for the application because the carbon graphite part runs against the material that is deposited on the countersurface.

As with any carbon part, oxidation can occur in the presence of oxygen at elevated temperatures. Material grades have differing maximum operating temperatures in an oxidizing and non-oxidizing environment. Oxidation inhibitor impregnations help raise this temperature limit in an oxidizing environment to delay the onset of oxidation.

Yes, there is no minimum temperature limit when running carbon graphite. However, depending on the application, different material grades can be more suitable for successful operation.

We offer a range of impregnations. Contact our Engineering department for help in determining which impregnation is best for your application.

  1. Antimony
  2. Babbitt
  3. Bronze
  4. Carbon
  5. Copper
  6. Nickel-Chrome
  7. Oxidation inhibitors
  8. Resin
  9. Silver

Yes, Metcar has complete machining capabilities. We manufacture carbon graphite and graphite material grades and can provide finished parts per our customer’s drawings and specifications. Get in touch with our engineers for more details on acceptable tolerances.

To recommend an appropriate material grade for your application, we need the following information:

-What is the application?

-Dry / wet running?

-Operating / max temp?

-Operating atmosphere?

-Operating fluid (chemical concentration if applicable)

-Shaft / rotating speed?

-Load?

-Expected life?

For custom machined parts, we will also need a drawing.

Yes, we have a range of material grades that are approved for use in food and pharmaceutical applications. We have material grades that are considered GRAS (Generally Recognized As Safe) by the FDA, as well as USP Class VI, NSF-51, and WRAS approvals.

Yes, we’re happy to provide recommendations for material, tolerances, finishes, running clearance, and press fits.

When running carbon/graphite we recommend a counter surface of Rc 35 or higher and a surface finish of 12 Ra or better. It’s important that the shaft material be corrosion resistant enough to prevent rusting or pitting.

No, there is no shelf life to carbon graphite parts or storage requirements.

Lead time varies based on material grade and part configuration. Lead time for blank materials is 1-2 days. Lead time for custom machined parts is 4–6 weeks depending on the material, size, and quantity. Speak to your customer service representative if you need parts sooner.

Yes, we accept Visa , Mastercard , and Amex credit card payments. To pay by credit card, you’ll have to fill out a credit card authorization form. There is also an 8% surcharge for credit card payments.

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