Ang bakal ay maaaring nahahati sa mababang carbon steel, medium carbon steel at high carbon steel. Mababang carbon steel - ang nilalaman ng carbon ay karaniwang mas mababa sa 0.25%; medium carbon steel - ang nilalaman ng carbon ay karaniwang nasa pagitan ng 0.25 at 0.60%; mataas na carbon steel - ang nilalaman ng carbon ay karaniwang mas malaki kaysa sa 0.60%.
Executive standard: aking bansa Taiwan CNS standard steel number S20C, German DIN standard material number 1.0402, German DIN standard steel number CK22/C22. British BS standard steel number IC22, French AFNOR standard steel number CC20, French NF standard steel number C22, Italian UNI standard steel number C20/C21, Belgium NBN standard steel number C25-1, Sweden SS standard steel number 1450, Spain UNE standard steel No. F.112, American AISI/SAE standard steel No. 1020, Japanese JIS standard steel No. S20C/S22C.
Komposisyon ng kemikal: Carbon C: 0.32～0.40 Silicon Si: 0.17～0.37 Manganese Mn: 0.50～0.80 Sulfur S: ≤0.035 Phosphorus P: ≤0.035 Chromium Cr: ≤0.25 Nickel Cu.2, mekanikal na katangian: ≤0.25 Nikel Cu.2 : Lakas ng tensile σb (MPa): ≥530 (54) Lakas ng yield σs (MPa): ≥315 (32) Pagpahaba δ5 (%): ≥20 Pag-urong ng lugar ψ (%): ≥45 Enerhiya ng epekto Akv ( J): ≥ 55 impact toughness value αkv (J/cm²): ≥69 (7) Hardness: unheated ≤197HB Sample size: sample size is 25mm Technical performance Pambansang pamantayan: GB699-1999
