One of the mostly widely used grades in India is high carbon spring steel wires grade SM- Medium Strength Static. These are cold drawn patented wires which are made from unalloyed high carbon steel wire rods and an ideal Carbon percentage ranging from 0.65% to 0.75% is maintained in this grade resulting in high strength and durability.
High carbon spring steel wires in Grade SM can be supplied in both phosphate and galvanized coating which possess properties for tension, compression or torsion springs which are subjected to medium-high static stresses and rarely dynamic stress.