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Carbon Brushes in Industrial Applications: Function, Materials, and Benefits

Reading time: 3 Minute(s)
Date: September 15, 2025
Electrical industry & IT
Energy
Life Science
Machine Design

Small but Critical: Carbon Brushes in Power Transmission

Carbon brushes – also known as sliding contacts – play a key role in transferring electric current between rotating and stationary components. They’re an essential part of electric motors and generators, ensuring continuous electrical connection even at high speeds. From power tools to wind turbines, carbon brushes are everywhere. At Schunk, we develop advanced, application-specific carbon brush solutions based on decades of material expertise and in-depth industry know-how.

Small but Critical: Carbon Brushes in Power Transmission

How Carbon Brushes Work: Reliable Contact at High Speeds

During operation, a spring presses the carbon brush against a rotating surface – typically a commutator or slip ring. This mechanical contact ensures consistent electrical conductivity, even under demanding conditions. The key lies in the material: graphite. Known for its excellent electrical conductivity and self-lubricating properties, graphite forms a thin film between the brush and the counter surface. This graphite film reduces friction and wear on both components. The brush wears down in a controlled manner, protecting more expensive parts like the commutator or slip ring from damage.

Materials Expertise: Custom-Tailored Solutions by Schunk

Different industrial environments require different types of brushes. That’s why Schunk offers a wide range of carbon brush materials, each designed for specific performance criteria:

  • Electrographite: Excellent temperature resistance and sliding properties
  • Metal-graphite: Low electrical resistance, ideal for high-current applications
  • Custom carbon blends: Tailored for mechanical durability and environmental resistance

To further enhance performance, brushes can include metallic components (e.g., copper or silver) and specially developed binders. Additionally, targeted impregnations – such as with resins, copper, or metal salts like antimony – can improve resistance to humidity, oxidation, and chemical exposure.

One example: Q-impregnation enhances the oxidation resistance of carbon, making the brush suitable for use in high-temperature environments.

As a recognized materials expert, Schunk leverages its extensive know-how to match brush materials and design precisely to your application – from compact tools to heavy industrial systems.

Custom Design: Engineering Brushes for Every Application

Beyond material selection, the shape, construction, and mounting of the brush are just as critical. Variables like available space, current load, vibration, pressure, and ambient temperature all affect the final design.

Whether you need a standard brush or a fully customized solution, Schunk develops each component to fit the exact requirements of your application. Features like dust grooves, special impregnation, and matching brush holders can be integrated as needed – ensuring optimal performance even in the harshest environments.

Where Carbon Brushes Are Used – From Household Tools to Wind Turbines

Carbon brushes are found across a wide range of applications, including:

  • Household appliances (e.g., vacuum cleaners, washing machines, blenders)
  • Power tools (e.g., drills, saws)
  • Automotive systems (e.g., starter motors, windshield wipers)
  • Power generation (e.g., wind turbines, turbo generators)
  • Heavy industry (e.g., steel mills, paper plants, mining equipment)
  • Electric rail systems and e-mobility

Depending on the application, current levels may range from just a few milliamps to several hundred amps. No matter the scale, carbon brushes are essential for stable and efficient electrical contact.

 Various carbon brushes with connection wires, springs, and metal holders for use in motors, generators, and current collector systems.

The Advantages of High-Quality Carbon Brushes by Schunk

  • Extended service life thanks to optimized graphite materials and advanced impregnation techniques
  • Low maintenance with longer replacement intervals and fewer unplanned downtimes
  • Protects commutators and slip rings due to self-lubricating materials and low contact wear
  • Reduced sparking and electromagnetic interference, improving operational safety
  • Reliable performance even in high-load or harsh environments

Conclusion: Small Component, Big Impact

Carbon brushes may seem simple, but their performance is crucial for the efficiency and reliability of electric machinery. When properly matched to the application, they minimize downtime, reduce operating costs, and extend equipment lifespan.

With Schunk as your partner, you benefit from advanced materials expertise and application-specific engineering – delivering exactly the right carbon brush for your needs.

Talk to Our Experts – Find Your Ideal Carbon Brush

Looking for the right brush for your application? Schunk offers a comprehensive portfolio of premium carbon brushes and custom solutions. Get in touch with our team to find out how we can support your system with the right materials and technology.

Interested in more information? Find all relevant brochures and documents on the topic of Carbon Brushes in Industry:

 

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