... . DIN Standard 10#(ST37-2,ST35-8),20#(ST42,ST45-4/8),45#(DIN CK45),16mn(ST52.4) etc.b. ... JIS Standard10#(STPG38,STS38,STB30,STB33,Stb35), 20#(STPG42,STB42,STS42,JIS S20C),45#(JIS S45C), 16mn(STS49,STPT49) etc.c ... ! SpecificationsChina StandardSteel GradeStandardseamless steel tubesand pipesfor structural purposeGB/T8162-199910, 20, 35, 45, 40Mn2, 45Mn2, 27SiMn, 20Cr, 40Cr, 20CrMo, 35CrMo, 38CrMoA1, ...