Freecutting steel wires are optimized for machining on automated machine tools. Their properties are achieved through alloying with lead or sulfur which leads to the formation of soft inclusions on which the chips can break.

Alloying with lead results in finely dispersed, heterogeneous lead inclusions in the steel on which the chips can break. Freecutting steels used at very high cutting rates are alloyed with lead.

Alloying with sulfur and manganese results in similar properties as with lead alloys. The sulfur creates soft, linear inclusions of manganese sulfide within the steel on which the chips break