AISI M2 high speed tool steel manufacturers and suppliers, supplied in round bar,square bar,flat bar,plate,sheet and wire.M2 is a molybdenum high speed steel,as a standard, it is most widely used industrial HSS.It has small and evenly distributed carbides giving high wear resistance, though its decarburization sensitivity is a little bit high.M2  has superior properties in toughness, wear resistance ,hardness and good machinability. Compared with T1, it is more economic ,its hardness is same as T1 after heat treatment,but its bending strength can reach 4700 MPa, and its toughness and thermo-plasticity are higher than T1 by 50%.M2 high speed steel

1.Supply Form & Size & Tolerance

Round bar
Diameter1-16mm10-50mm50-180mm180-300mm
ProcessCold DrawnHot RolledHot ForgedFree Forging
Flat bar
Thickness1-2.5mm1.5-20mm20-300mm
WidthMax 800mmMax 800mmMax 800mm
ProcessCold DrawnHot RolledHot Forged

Remark:Tolerance can be customized as per requests

2.Chemical Composition

StandardGradeCMnPSSiCrVMoW
ASTM A600M20.78-0.880.15-0.40.030.030.2-0.403.75-4.501.75-2.24.5-5.55.5-6.75
DIN EN ISO 49571.33430.86-0.940.400.030.030.453.80-4.501.70-2.04.7-5.26.0-6.70
JIS G4403SKH510.80-0.880.400.030.030.453.80-4.501.70-2.14.5-5.55.9-6.70
GB/T 9943W6Mo5Cr4V20.80-0.900.15-0.40.030.030.2-0.453.80-4.401.75-2.24.5-5.55.5-6.75

3.Physical Property

Density,g/cm38.1
Melting point,°C1430
Modulus of elasticity,N/mm2217 x 10^3
Thermal conductivity,W/m °C19
Specific heat,J/kg °C460
Electrical Resistivity,ohm*mm2/m0.54
Machinability50-60% of a 1% carbon steel

4.Thermal Expansion

Temperature
10^-6 m/(m*K)

10^-6 in/in °F
°F°C
21210011.56.5
39220011.76.6
57230012.26.9
75240012.47
93250012.77.1
1112600137.3
129270012.97.3

5. Mechanical Property

Hardness, Rockwell C (tempered at 620°C, quenched at 1200°C)62
Hardness, Rockwell C (as hardened, quenched at 1200°C)65
Compressive yield strength (when tempered at 150°C)3250 MPa
Izod impact unnotched (when tempered at 150°C)67 J
Abrasion (loss in mm 3 , as-hardened; ASTM G65)25.8
Abrasion (loss in mm 3 , tempered at 690°C; ASTM G65)77.7
Poisson's ratio0.27-0.30
Elastic modulus190-210 GPa

6.Forging

Pre heat the AISI M2 with two steps.First,heat slowly and uniformly to 850-900°C with a rate not exceeding 220°C per hour,second,heat more quickly to the forging temperature of 1050-1150°C.Re-heating is necessary when temperature below 850°C. Slow cooling in furnace after forging.

7.Annealing

Annealing must be performed after hot working and before re-hardening.Heat the temperature to 770 to 840°C with a rate not exceeding 220°C per hour.Controlled slow cooling in furnace at 10 to 20°C per hour to approximately 600°C, followed by cooling in still air. Hardness after annealing 269 Brinell, maximum.

8.Stress Relieving

It is recommended to stress relieve after machining and prior to hardening to minimise the possibility of distortion.Heat in a neutral atmosphere to the  temperature of 600 to 650°C, and  soak for approximately two hours,followed by slow cooling in the furnace.

9.Hardening

Preheat in multiple steps and equalize surface and core temperatures,first step with 550°C,second step with 850°C,third step with 1050°C,then to the appropriate hardening temperature 1190 to 1230°C.

Quench in: oil, salt bath at 500 to 550°C, or vacuum. The upper temperature range should be used for parts of simple geometry, the lower range for more complex tooling. For cold work tooling, lower temperatures are of importance for improved toughness.

9.Tempering

Tempering should be carried out immediately after quenching. Heat slowly and uniformly to the tempering temperature,soak well not less than 2 hours(one hour per 25mm of total thickness).First and second tempers is required to reach the desired hardness level, and the third selected for additional stress relief at 30 to 50°C below the highest tempering temperature. Intermittent cooling, in air, between tempers is required for a minimum of 1 hour. Obtainable hardness of 64 to 66 HRC.

Hardening Temperature,°F
Double Tempering Temperature,°F215022002225
80061HRC61.5HRC62HRC
85061.5HRC62HRC62.5HRC
90062.5HRC63HRC63.5HRC
95063HRC64HRC65HRC
100064HRC65HRC65.5HRC
102563.5HRC65HRC65.5HRC
105063HRC64.5HRC65HRC
110061.5HRC62.5HRC63.5HRC
115057.5HRC59HRC60HRC
120051HRC54HRC55HRC

10.Application

AISI M2 is used in a wide used for all kinds of cutting tool, cold forming tools,punch and die applications.

Typical use include:twist drills, reamers, broaching tools, taps, milling tools, metal saws,knife,and etc.