Brush – TN59431

A carbon brush rides against the commutator of an electric motor, carrying current into the spinning armature through a sliding contact that is meant to wear as a sacrificial part. The brush is deliberately softer than the commutator, so it, rather than the motor, gives up material over thousands of hours of running.

As it wears down it loses contact pressure, and the motor begins to spark, run weak, or cut out, which is the point of replacement. Renewing brushes at the first sign of wear protects the commutator underneath, which is far costlier to service than the brushes themselves.

Match the brush dimensions, lead position, and any spring or terminal configuration to the brush coming out, since a carbon brush is defined by the holder it slides in and the connection it makes.