AISI M2 • JIS SKH51 • DIN 1.3343 Steel

What is M2 Steel?

M2 tool steel is tungsten-molybdenum high-speed steel with a well-balanced carbon composition and high toughness. It is also called JIS SKH51 and DIN 1.3343 steel. It is easy to overheat, control the quenching heating temperature is necessary and the heat treatment protection requirements are strict. It is used widely to make cutting tools because of its great hardness and wear resistance. It has replaced T1 high speed steel in most applications, become the first choice of customer due to its great performance and extremely high performance price ratio. Steel properties and heat treat as below.

M2 Steel Grade Equivalent Chart

StandardASTM A600-92aEN ISO 4957-1999JIS G4403-2006ISO 4957-1999
GradesM2(Standard C)HS 6-5-2SKH51HS 6-5-2

M2 Steel Chemical Composition

ASTM A600-92a0.78-0.880.15-0.40Max 0.03Max 0.030.20-0.453.75-4.501.75-2.205.50-6.754.50-5.50
EN ISO 4957-19990.80-0.88≤0.40≤0.030≤0.030≤0.453.80-4.501.70-2.105.90-6.704.70-5.20
JIS G4403-20060.80-0.88Max 0.40Max 0.030Max 0.030Max 0.453.80-4.501.70-2.105.90-6.704.70-5.20
ISO 4957-19990.80-0.88≤0.40--≤0.453.80-4.501.70-2.105.90-6.704.70-5.20

1.3343 Steel Physical Properties

Physical propertiesMetricImperial
Density8.16 g/cm³0.294 lb/in³
Melting point4680°C2600°F

M2 Steel Mechanical Properties

Mechanical propertiesMetricImperial
Hardness, Rockwell C(tempered at 1150°F, quenched at 2200°F)6262
Hardness, Rockwell C(as hardened, quenched at 2200°F)6565
Compressive yield strength(when tempered at 300°F)3250 MPa471000 psi
Izod impact unnotched(when tempered at 300°F)67 J49.4 ft-lb
Abrasion(loss in mm3, as-hardened; ASTM G65)25.825.8
Abrasion(loss in mm3, tempered at 1275°F; ASTM G65)77.777.7
Poisson's ratio0.27-0.300.27-0.30
Elastic modulus190-210 GPa27557-30458 ksi
m2 tool steel

1.3343 Steel Characteristics

  1. Hardness(Factory original status): ≤255HB
  2. Hardening temperature: 1220℃-1240℃
  3. Hardness(After heat treatment): ≤63HRC
  4. It is a great choice at cutting applications due to its great wear resistance and toughness.
  5. Carbide uniformly distributed and high toughness.
  6. Can be used to make milling cutters, reamers, broaches, gear cutters and other industry tools.

M2 Steel Heat Treatment and Produced


The shaping of M2 tool steels may be executed using grinding strategies. But, which has bad grinding capability. So they’re called 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 to 1600° F, soak thoroughly at heat. Furnace cool 25° F per hour to 900° F, air cool to room temperature. Approximate annealed hardness 241 Maximum Brinell.

Stress Relief of Unhardened Material: Heat slowly to 1200 to 1250° F. Soak for two hours per inch of thickness at heat. Slow cool(furnace cool if possible) to room temperature.


Heat M2 steel slowly to 1550° F, soak fully, heat to 1850° F, soak thoroughly. Soak time in the furnace varies from a few minutes to 15 minutes, depending on tool size, the heat capacity of the furnace, and the size of the charge. – Heat to 2150 to 2200° F for max. toughness and minimum distortion. – Heat to 2250 to 2275° F for max.


Double tempering is necessary, sometimes preferred three times tempering. Soak for 2 hours per inch of thickness. Air cool to room temperature between tempers. The best tempering range for hardness, strength and toughness is 1000 to 1050° F.


For full hardness, need to oil quench to 150-200° F. Air quenches to 150° F. When quenching in hot salt maintains the quench just above the Ms temperature. After equalizing withdraw parts from the hot salt and air cooled to 150° F.

M2 Steel Heat Treatment

M2 steel is preheated prior to hardening at 2610 ° C(4730 ° F). Then heated rapidly from 2610 ° C (4730 ° F) to 3960 ° C (7160 ° F). The steel is finally cooled for 3 to 5 minutes and quenched in air, salt bath or oil.

Steel Packing
Steel Transportation

M2 Steel Quality Certificate

M2 steel quality certicficate

1.3343 Steel Application

The application is decided by M2 steel chemical composition and properties. It has high hardness, red hardness. Good thermoplasticity and excellent toughness. It is used to make tools that require has good wear resistance and toughness which can sustain large impact forces. Such as pinion cutters, planers, milling cutters, turning tools, drill bits and etc.

M2 Tool Steel Supply

Round Bar

Specification: Dia 12-220mm; Length: Can be customized
Surface: Black Surface/Bright Surface /Grinded/Peeled/Turned


Specification: thickness: 3-200mm; width: Can be customized; length: Can be customized
Surface: Black Surface/Bright Surface /Grinded/Peeled/Turned


We have our own cutting and processing equipment. Specifications can be cut and customized according to your requirements.

We are a professional special steel stockist and supplier with a high-quality stand for many years. As a professional M2 steel supplier, please contacts us for any request of AISI M2/DIN 1.3343 steels materials. Songshun Steel always with you.

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