Abstract: A cartridge brush assembly for fractional horse power commutated motors comprises an elongated tubular holder 17 with opposed sidewalls 31, 33 spaced transverse to a commutator rotational axis 15. A brush 19 is slidably mounted in holder 17 and protrudes through a mouth 35 of holder 17 for engaging a commutator 13. A guide 21 is slidably mounted in holder 17 and comprises a pair of spaced rounded feet 57, 59 slidably and pivotally engaging a chamfered rear face 49 of brush 19. A spring 23 biases a transversely spaced brush sidewall 45 against a transversely spaced holder sidewall 31 and biases brush 19 into engagement with commutator 13. The brush assembly reduces chattering and misalignment of the brush over the life of the brush.