BS4659 BD3 Apparatus Steel

Pre-heat at 900-950°C then raise to 1050-1100°C. Final forging should not be done below 900°C.

AS BD3 is supplied in the annealed and machineable condition re-annealing will only be necessary if the steel has been forged or hardened. Heat slowly and uniformly to 850-870°C. Soak for three to four hours and allow to cool in the furnace. Re-heat and again soak for three to four hours. Allow to cool in the furnace to room temperature.

Stress relieving of BD3 should be done after rough machining. To stress relieve, heat the tool steel component to 600-650°C. Soak well and cool in the furnace or in air then finish machined before hardening.

Temper BD3 tool steel with the least possible delay after hardening, preferably when the steel is hand warm. Select a suitable tempering temperature between 150-220°C or 450-550°C. The lower tempering range is used for BD3 when maximum hardness is required and the higher tempering range should be used when maximum toughness is required. When the tool steel has reached the required temperature, soak for at least one hour per 25mm of section. Double tempering is recommended.

Pre heat the steel to 750-800°C. and allow to soak at this temperature. The tools may then be brought up to 950-1000°C. Soak thoroughly for thirty minutes per 25mm of ruling section, then cool or quench accordingly. It is important not to exceed 1000°C when heating for hardening.

Heat treatment temperatures, including rate of heating, cooling and soaking times will vary due to factors such as the shape and size of each BD3 steel component. Other considerations during the heat treatment process include the type of furnace, quenching medium and work piece transfer facilities. Please consult your heat treatment provider for full guidance on heat treatment of tool steels.

BS4659 BD3 tool steel is supplied in accordance with our ISO 9001 : 2008 registration.