The mechanochemical wear of multicomponent glasses was studied under controlled humidity conditions using a reciprocating ball-on-flat tribometer. For dry conditions, the surfaces were extensively damaged by scratching for all of the glasses, while for humid conditions the wear behaviour varied with the glass composition suggesting a chemical effect on scratch behaviours of glass surfaces. The wear of soda lime silica glass was suppressed with increasing humidity, while the borosilicate and barium boroaluminosilicate glasses showed an increase in the wear volume with increasing humidity. The unique humidity dependence of the observed mechanochemical wear of soda lime silica glss supports the hypothesis that hydronium ion formation in the sodium-leached sites of the soda lime glass enhances its wear resistance.