EN 24

Grade Introduction:

EN24 Alloy Steel is a very high-strength steel alloy that is supplied hardened and tempered. The grade is a nickel-chromium molybdenum combination – this offers high tensile steel strength, with good ductility and wear resistance characteristics. With relatively good impact properties at low temperatures, EN24 is also suitable for a variety of elevated temperature applications

Grade Application:

  • High strength shafts
  • Punches & dies
  • Drill bushings
  • Retaining rings
  • Gears

Equivalent grades:

  • BS 970:1955 EN24T
  • BS 970:1991 817M40T
  • German / DIN 34CrNiMo6
  • French AFNOR 35NCD6
  • American AISI / SAE 4340
  • German Werkstoff No. 1.6582
  • European Standard EN10277-5

Chemical composition:

The following table shows the chemical composition of En24 steel:

Element C Si Mn P S Cr Mo Fe
Content (%) 0.36-0.44 0.10-0.35 0.45-0.70 0.035 Max 0.040 Max 1.00-1.40 0.20-0.35 1.30-1.70


248 – 302

Heat Treatment :

Heat treatment temperatures, including rate of heating, cooling and soaking times will vary due to factors such as the shape and size of each steel component. Other considerations during the heat treatment process include the type of furnace, quenching medium and work piece transfer facilities.


  1. Nominal normalizing temperature:840-900°C.
  2. Hold the temperature for several hours.
  3. Cooling in the air.