1.Mild (low carbon) steel: approximately 0.020% to 0.25% carbon content with up to 0.4% manganese content.
Less strong but cheap and easy to shape; surface hardness can be increased through carburizing.
2.Medium carbon steel: approximately 0.14% to 0.84% carbon content with 0.60 to 1.65% manganese content.
Balances ductility and strength and has good wear resistance; used for large parts, forging and car parts.
3.High carbon steel: approximately 0.59% to 0.65% carbon content with 0.30 to 0.90% manganese content.
Very strong, used for springs and high-strength wires.
4.Very high carbon steel: approximately 0.96% to 2.1% carbon content, specially processed to produce specific atomic and molecular micro structures.