MACO was the first manufacturer of accessories for windows who in 2000 introduced passivation with chrome VI free silver to the zinc plating process, with the subsequent application of a silicate base of sealing film.  This technique has provided excellent results in the improvement of characteristics of the surfaces and represented the first valid alternativa to the chrome plating process with hexavalent chromium.

The hardware made from steel and/or zamak alloy is zine plated, passivated and sealed.

Passivation with a thick layer and sealing provide the components with greater resistance to corrosion and the typical aspect of zinc covering to metal.