SK4
Carbon tool steel
Standard: JIS G4401
Features and Scope
SK4 steel, strength and wear resistance than high T8 and T9, but the hot hardness is low, not high hardenability and hardening deformation. SK4 suitable for the manufacture of cutting conditions are poor, higher wear resistance, and is not a sudden and severe vibrations, requires a certain toughness and a sharp knife-edge tools such as lathe, planer, drill, cutter, low accuracy and measuring simple shapes (such as card board, etc.), can be used without a large impact on the wear-resistant parts.
Chemical composition
Carbon C: 0.95 ~ 1.04
Si Si: ≤ 0.35
Manganese Mn: ≤ 0.40
Sulfur S: ≤ 0.030
Phosphorus P: ≤ 0.035
Chromium Cr: allow the residual content of ≤ 0.25, ≤ 0.10 (when manufacturing lead bath quench wire)
Ni: to allow the residual content of ≤ 0.20, ≤ 0.12 (when manufacturing lead bath quench wire)
Copper Cu: to allow the residual content of ≤ 0.30, ≤ 0.20 (when manufacturing lead bath quench wire)
Note: The allows the residual content of Cr + Ni + Cu ≤ 0.40 (when manufacturing lead bath quench wire)
Hardness: Annealed, ≤ 197HB, indentation diameter ≥ 4.30mm; quenching, ≥ 62HRC
