Abstract: In accordance with a preferred embodiment of this invention, a commutator for electrical machines having a polymeric spool and aluminum alloy bars uniformly spaced around its periphery is formed. This commutator is useful in low voltage applications wherein the applied or produced voltage may vary from 3 to 30 volts. A critical feature in forming this commutator is the combination of an electrolytic etch and an electrolytic oxide formation on the surface of the aluminum alloy bars. This combination of steps provides means for bonding the aluminum alloy bars to the polymeric spool and also lowers the electrical resistance of alumina. In addition, alloying elements, preferably iron, increase the conductivity of the alumina layer and directionally balance the electrical resistance across the aluminum-alumina junction.