12 15 belongs to American free-cutting steel, and the implementation standard is ASTM A29/A29M-20 15.
Free-cutting steel is an environmentally friendly material. Compared with 12L 14, it contains no lead and is harmful to the environment, and has good processability. Suitable for general electroplating shafts, cutting materials and general parts. Because of its precise precision and good surface condition, free-cutting steel products can be used directly.
The chemical composition of 12 15 is as follows: