Is graphite conductive or insulating?

The short answer: it depends on direction. Graphite conducts very well in the plane of its hexagonal layers and behaves almost like an insulator when current must cross those layers perpendicularly.

Why does it conduct in one direction and not the other?

Carbon atoms form flat sheets with strong in-plane bonds. Between sheets, bonds are weak and allow few electrons to pass. Electrical and thermal conductivity are high parallel to the basal plane and low perpendicular to it.

Unlike diamond — an insulator — graphite moves charge mainly within each layer. That makes it useful where controlled wear and good electrical contact are needed, such as motor brushes.

Industrial uses of graphite conductivity

• Alkaline and lithium-ion batteries: graphite powder as a conductive additive in cathodes or as active material in anodes, depending on cell design.
• Carbon brushes: electrical connection between rotor and fixed circuit in DC and AC motors.
• Contacts, seals, and electrodes: chemical stability and conductivity oriented to the working plane.

Other related properties

Besides anisotropic electrical conductivity, graphite is refractory, resistant to many chemical agents, and stable under thermal shock. In the glass industry, parts withstand temperature and allow hot glass to slide on treated surfaces.

Limitations to consider

Conductivity and wear depend on grade, grain orientation, contact pressure, and operating atmosphere. Perpendicular-to-grain paths should not be assumed to conduct like in-plane paths without verifying the design.

Information needed for a quote

To guide selection or prepare a quote, ESGRAF typically needs:

• Application and operating conditions (temperature, atmosphere, load).
• Dimensions, technical drawing, or CAD file when applicable.
• Required quantity.
• Requested grade or material currently in use.
• Observed issue with the previous part or lubricant, if any.

Request a quote

To recommend grade and format, share your application, operating conditions, quantity, and drawings when available. Contact ESGRAF and a specialist will guide you based on your process.

We supply powders, lubricating suspensions, brushes, and EDM electrodes.