(1) ordinary steel, carbon structural steel: A. (a) Q195 (b); Q215 (A, B); (c) Q235 (A, B, C); (d) Q255 (A, B); (E) Q275. A common structure steel low alloy structural steel B. C. specific purpose (2) high quality steel (including senior high quality steel structure steel a.): (a) quality carbon structural steel; (b) alloy structural steel, spring steel; (c); (d) free-cutting steel; (E) bearing steel (f); the specific use of high-quality structural steel. The B. tool steel: (a) carbon tool steel; (b) alloy tool steel; (c) high speed tool steel. C. special steel performance: (a) stainless steel (b); heat resistant steel; (c) electric heating alloy steel; (d) electrical steel; (E) high manganese wear-resistant steel.