40CrMnMoS8-6 Steel

40CrMnMoS8-6 steel suppliers delivering throughout the UK. West Yorkshire Steel are stockholders and suppliers of round, flat bar, plate and block. 40CrMnMoS8-6 is high tensile steel popular for plastic mould applications.

Form of Supply

West Yorkshire Steel are stockholders and suppliers of round bar, flat bar, plate and block. Rectangular pieces can be sawn to your specific sizes. Diameters can be sawn to your required lengths as one offs or multiple pieces. Precision ground bar can be supplied, providing a quality precision ground bar to close tolerances.

Contact our experienced sales team who will assist you with your 40CrMnMoS8-6 steel enquiry.

  • Plate
  • Flat
  • Diameter

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This grade is commonly used for the production of moulds where improved machinability is required. Typical applications include die holders, zinc die casting dies, backers, bolsters and injection moulds. The versatility of this plastic mould tool steel with its high tensile strength enables uses for a variety of other applications such as shafts and wear strips.

Carbon 0.35-0.45% Chromium 1.80-2.00%
Manganese 1.40-1.60% Molybdenum 0.15-0.25%
Sulphur 0.05-0.10% Silicon 0.30-0.50%
Phosphorous 0.03% max

Heat slowly, allowing sufficient amount of time for the steel to become heated through. Forge at 1050°C, do not forge below 930°C reheating if necessary. Cool very slowly after forging.

When the steel is heavily machined, stabilising just before finish machining is recommended to relieve machining strains. Heat to 460-500°C. Soak well and allow to air cool.

Heat uniformly to 710 to 740°C. Soak well, slowly cool in the furnace.

Heat uniformly to 830 to 870°C until heated through. Quench in oil.

Heat uniformly and soak at the tempering temperature for at least one hour per 25mm of ruling section. Allow to cool in still air.

Temperature [°C] 100 200 300 400 500 600
Hardness [HRc] 51 50 48 46 42 36
Tensile [N/mm²] 1730 1670 1570 1480 1330 1140

Induction or flame hardening of will achieve a hardness of 50 to 55HRc. It is preferable to air cool, though smaller components may require forced cooling. Temper immediately after hardening.

Heat treatment temperatures, including rate of heating, cooling and soaking times can 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 also the work piece transfer facilities. Please consult your heat treatment provider for full guidance on hardening of 40CrMnMoS8-6.

40CrMnMoS8-6 steel is supplied in accordance with our ISO 9001:2008 registration.