Carbon brushes are wear parts in electric motors. They continuously rub against the commutator during operation, transmitting current to the rotor windings. With increased use, carbon brushes gradually wear down and shorten, resulting in insufficient spring pressure and poor commutator contact

When carbon brushes wear to their limit, motor operation becomes unstable—sometimes running normally, sometimes stopping, and sometimes requiring manual rotation of the brush head to restart. Replacing the carbon brushes restores stable conductive contact, allowing the motor to function normally again

The tension spring is a key component in maintaining contact between the carbon brushes and the commutator. If the spring detaches from the carbon block, simply twist it back into place. If the spring is tangled, gently straighten it to avoid overstretching and causing deformation or failure

A pack of 10 is sufficient for one hair clipper for several years, or for maintaining multiple devices simultaneously. Hair clippers and pet clippers typically require carbon brush checks every 1-2 years; a pack of 10 avoids the inconvenience of frequent purchases

Before replacing the carbon brushes, it is recommended to clean the surface of the motor commutator to remove carbon deposits and copper shavings. Gently buffing the commutator surface with fine sandpaper until it shines can extend the life of new carbon brushes and restore the motor to its optimal performance