Schwefel S:
- improves machinability, this leads to short-brittle chips, as MnS (manganese sulfide) makes the material brittle, see also their influences in free-cutting steel
- combines with iron (Fe) to form iron sulfide (FeS ) - this results in a possible risk of red fracture;
- even more reactive with manganese, resulting in the formation of manganese sulfide ( MnS ), this in turn blocks or decimates the possible formation of iron sulfides (FeS)
