... carbon structural steel high quality1.10#,20#,25#,30#,35#,40#,45#,50#,2. Q195-Q275,40Cr,20-42CrMo,20-30CrMnTi DescriptionCarbon structure steel/carbon steel ... round bar/flat bar/carbon steel plate/sheetGradeGB Q255/JIS SS490/DIN S275J0/ASTM ...