Manganese is a brittle, metallic element that exists in the ore of pyrolusite. When making steel, it reacts with sulfur and helps to increase the metal's resistance to heat. Atomic number 25, atomic weight 54.9380. Phosphorus is a poisonous, nonmetallic element that helps protect metal surfaces from corrosion. Atomic number 15, atomic weight 30.9738.
Sulfur is a nonmetallic element found mainly in volcanic and sedimentary deposits.
Sulfur, in the form of iron sulfide, can cause steel to be too porous and prone to cracking. Atomic number 16, atomic weight 32.064. Silicon is the second most abundant element in the earth's crust and can be found in rocks, sand and clay. It acts as a deoxidizer in steel production. Atomic number 14, atomic weight 28.086.