Ferro manganese is used mainly to counteract the bad effects of sulfur. It also acts as a deoxidizer and combines with sulfur, thereby improving the hot-working properties of the product. It imparts metallurgical properties such as increased strength, hardness toughness and hardenability.

Manganese has an important influence on the structure and properties of steel, depending on the amount used and the combined effect with other alloying elements. Among all other alloying elements, manganese has the strongest effect on the hardenability of steels.

Manganese improves the tensile strength, workability, toughness, hardness and resistance to abrasion. It also reacts with the remaining sulphur in the steel, thus preventing hot shortness.