Hot Rolled Spring Steel (IS : 3431-1965)
 
Designation of Steel Grade C % Mn % Si % S % Max. P % Max. Cr % V % Typical Applications
50 Cr IV 23 1 0.45-0.55 0.50-0.80 0.10-0.35 0.050 0.05 0.90-1.20 0.1-0.30 In the form of bars and flats for volute, helical and leminated spring for automotive suspension
55 Si 2 Mn 90 2 0.50-0.60 0.80-1.00 1.50-2.00 0.050 0.50 - -