 AISI M2
(High Speed Steel For Cold Work Applications)
Applications
M2 is suitable for cold work applications, for example tools for punching, forming and pressing, etc. M2 possesses an admirable combination of wear resistance, toughness and compressive strength. This combination of properties makes it superior to many high alloyed cold work steels.
Properties
Special Properties
M2 is medium-alloyed and has good machinability. Its composition makes for a good combination of toughness, wear resistance and compressive strength. By virtue of these well-balanced properties M2 has come into very wide use for all cutting tools.
Methods of making tools
M2 can be worked in the same way as other high-speed steels by plastic forming, machining, grinding, electrical discharge machining, welding and polishing. M2 is amenable to cold forming. In grinding, local heating of the surface, which might alter the temper, must be avoided. Grinding-wheel makers can furnish advice on the correct choice of grinding wheels. Machining is carried out using carbide or high-speed steel tools.
Heat Treatment
- Soft-annealing 1560-1650°F/850-900°C, slow cooling 18°F/10°C/h to 1290°F/700°C, hardness max 255 Brinell.
- Stress relieving 1110-1290°F/600-700°C, approx. 2 hours at temperature, slow cooling to 930°F/500°C.
- Hardening with preheating in two steps 840-930°F/450-500°C, 1560-1650°F/850-900°C and austenitizing at 1920-2230°F/1050-1220°C. Austenitizing and cooling preferably in a salt bath. Cool to hand warmth.
- Tempering at 1000°F/540°C or higher, a minimum of 2 times, for at least 1 hour at full temperature is recommended.
Surface Treatment
M2 can be nitrided or steam-tempered if so desired. When nitrited, a small diffusion zone of .00008-.0008 inches (2-20µm) is recommended. M2 is good as a substrate material for PVD and CVD coating.
Further Information
Please contact us for further information on the selection, heat treatment and availability of tool steels from Uddeholm.
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AISI M2 Data Sheet
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