Standard: Deutsche industrie normen DIN 17175 Uses:Seamless Tubes OF Heat-resistant Steels. Chemical Composition(%): Grade C Si Mn S P Cr Mo V Standard Steel grade Max DIN 17175 St35.8 =0.17 0.10-0.35 0.40-0.80 0.02 0.025 – – – St45.8 =0.21 0.10-0.35 0.40-1.2 0.02 0.025 – – – 15Mo3 0.12-0.20 0.10-0.35 0.40-0.80 0.02 0.025 – 0.25-0.35 – 13CrMo44