Chemical composition (%)
SKH51 is a high-speed steel, Japanese JIS grades, equivalent to the German DIN 1.3343, the United States, M2, our W6Mo5Cr4V2.
  C 0.80 ~ 0.9
Mn 0.15 ~ 0.40
  Si 0.2 ~ 0.45
  Cr 3.80 ~ 4.4
  Mo 4.5 ~ 5.5
  V 1.75 ~ 2.2
      W 5.5 ~ 6.75
  P ≤ 0.030
  S ≤ 0.030
  Ni ≤ 0.3
  Cu ≤ 0.25

Features:
Red hot high hardness, high wear resistance and cutting ability, high impact toughness, uniform fine grain, high toughness. SKH-51 tool steel for the high-speed steel, tungsten steel, appropriate for manufacturing powerful cutting wear resistance, impact tools, high-level die, screw mode, the more complex needs toughness and shape tools, milling cutters, drills, etc.
Uses:
Tool industry: scraper, roller cutter, cutter, drill, etc.
Forging industry: forging die
  Screw Industry: hexagonal, etc. starts with molding, dental attack, punch
Heat treatment temperature and reference methods: annealing: temperature 800 ~ 880 ℃, to 10 ~ 20 ℃ / Hr furnace cooling to about 600 ℃, the hardness of HB269 the following; stress relief: temperature 650 ~ 750 ℃, furnace cooling quenching: Preheat 1 : temperature of 550 ~ 600 ℃, for 30 minutes warm-up for each 25mm 2: temperature 850 ~ 900 ℃, each 1mm for 20 to 30 seconds warm-up 3: temperature 1050 ~ 1100 ℃, each 1mm for 20 to 30 seconds, suitable for large-scale complex parts of Austenitic iron: Temperature 1170 ~ 1240 ℃, each 1mm for 10 to 15 seconds quenching medium: oil, hot bath, air or gas; tempering: temperature 540 ~ 570 ℃, 25mm for 60 minutes each, back to the more than 3 times the number of fire, hardness HRC64 or more. In steel molds generally not as the main material used, only material used as an attachment. Mold ejector generally use carbon tool steel, such as the use T10A steel, it is worth noting that taking salt water - liquid quenching oil double bending deformation, and should be replaced by nitrate levels quenching bath, bath alkali or alkaline bath quenching Ms classification classification quenching three methods, the ejector hardness 53-58HRC, quenching can reduce the mandrel bending.