Chemical composition
(Wt) (%) C :0.28-0 .38 Mn :0.50-0 .80 Si: ≦ 0.35 S: ≦ 0.050 (A grade)
P: ≦ 0.045

Mechanical properties
Tensile strength (σb / MPa) :490-630


Elongation (δ5 /%):


≧ 20 (a ≦ 16mm), ≧ 19 (a> 16-40mm)


≧ 18 (a> 40-60mm), ≧ 17 (a> 60-100mm)


≧ 16 (a> 100-150mm), ≧ 15 (a> 150mm)


Where A is a steel thickness or diameter.


Elongation (δ5 /%):


≧ 26 (a ≦ 16mm)


≧ 25 (a> 16-40mm)


≧ 24 (a> 40-60mm)


≧ 23 (a> 60-100mm)


≧ 22 (a> 100-150mm)


≧ 21 (a> 150mm)


Where A is a steel thickness or diameter.