M42 HIGH SPEED STEEL (1.3247)

Material available in round and flat sections

M42 High Speed Steel (1.3247) is a highly cobalt alloyed High-Speed Steel to be used when the demand for hot hardness is of great importance. M42 High Speed Steel (1.3247) has a good machinability and a good wear resistance.

Applications

For use on:

Physical Properties

Temperature	20°C	400°C	600°C
Density g/cm3	8	7.9	7.9
Modulus of elasticity kN/mm²	225	200	180
Thermal expansion ratio per °C	-	11.5x10 -6	11.8x10 -6
Thermal conductivity W/m°C	24	28	27
Speciﬁc heat J/kg°C	420	510	600

4-Point Bend Strength

Hardening temperature in °C

Tempering 3 x 1 hour at 560°C

Dimension of test piece Ø 4.7 mm

Rmb = Ultimate bend strength in kN/mm²

Reb = Bend yield strength in kN/mm²

Tot. work = Total work in Nm

Heat Treatment

Soft annealing in a protective atmosphere at 850-900°C for 3 hours, followed by slow cooling 10°C per hour down to 700°C, then air cooling.
Stress-relieving at 600°C to 700°C for approximately 2 hours, slow cooling down to 500°C.
Hardening in a protective atmosphere with pre-heating in 2 steps at 450-500°C and 850-900°C and austenitizing at a temperature suitable for chosen working hardness.
Tempering at 560°C three times for at least 1 hour each time.

Surface Treatment

The steel grade is a perfect substrate material for PVD coating. If nitriding is requested, a small diffusion zone is recommended but avoid compound and oxidized layers.

Guidelines For Hardening

Tempering temperature in °C

Hardness after hardening, quenching and tempering 3 x 1 hour

Tool	Hardening	Tempering
Single-edge cutting tools	1190°C	560°C
Multi-edge cutting tools	1150-1180°C	550-570°C
Cold work tools	1050-1150°C	550-570°C

We supply a comprehensive range of special steel products.

Whether you need tool steels, conventional high-speed steels, or powder metallurgy grades, our friendly team is ready to help meet your requirements. We cut and supply steel products for our customers, across the UK and Ireland, and specialise in niche products as well as standard commercial grades.