Japanese SK-4F free-cutting steel

Chemical composition:

C 0.70 - 0.80,

Si ≤ 0.25,

Mn 0.40 - 0.70,

S 0.16 - 0.24

P 0.04 - 0.09

    Japan imports SK-4F (equivalent to 20AP) high-precision grinding rod, shaft parts are widely used, especially for higher surface hardness after heat treatment of thin small shaft parts.