Low the parathion composite cutting steel, the cutting performance is better than on the 20th of steel less than Y12 steel, but the mechanical performance of the Y20 than Y12 steel. Machining after forming carburizing treatment can be used to make a hard surface and high center of toughness instrumentation parts and shaft wear. 

 Chemical composition: carbon, the C: 0.17 ~ 0.25 Si Si: 0.15 ~ 0.35 Mn Mn: 0.70 ~ 1.00 Sulfur S: 0.08 to 0.15 Phosphorus P: ≤ 0.06 
 Mechanical properties: tensile strength σb (MPa): (hot) 450 600; (cold drawn) steel thickness or diameter of 8 to 20: 570 ~ 785;> 20 to 30: 530 ~ 745;> 30: δ5 of 510 ~ 705 elongation (%): (hot) ≥ 20; (cold) ≥ 7.0 Reduction of the rate of ψ (%): (hot) ≥ 30 Hardness: (hot) ≤ 175HB; (Cold Drawn ) 167 ~ 217HB