M2 High speed steel | 1.3343 steel | HS-6-5-2C | SKH51
M2 molybdenum high speed tool steel, which has high carbon content and better wear resistance than M1 molybdenum high speed tool steel.
Designation by Standards
Chemical Composition (%)
Physical Properties
The physical properties of M2 molybdenum high speed tool steel are given in the following table.
Mechanical Properties
The mechanical properties of M2 molybdenum high speed tool steel are tabulated below
Thermal Properties
The following table shows the thermal properties of M2 molybdenum high speed tool steels.
Machinability
Shaping of M2 tool steels can be carried out using grinding methods. However, they have poor grinding capability and hence they are regarded as "medium" machinability tool steel under annealed conditions. The machinability of these steels is only 50% of that of the easily machinable W group or water hardening tool steels.
Heat Treatment
M2 tool steels are pre-heated prior to hardening at 815.5°C (1500°F) followed by rapid heating from 815.5°C (1500°F) to 843.3°C (1550°F). These steels are then cooled for 3 to 5 min and quenched in air, salt bath, or oil.
Annealing
ASTM M2 tool steels are annealed at approx 885°C (1625°F) and cooled at 72°C (162°F) per hour or even less.
Tempering
ASTM M2 steels are tempered at 565.5°C (1050°F) to obtain Rockwell C hardness from 60 to 65.
Hardening
Finally, M2 steels are hardened by heat treatment and quenching.
Applications
ASTM M2 tool steels are suitable for making cutting tools.