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SAE-AISI M7 (T11307) Molybdenum High-Speed Steel

SAE-AISI M7 steel is a tool steel. M7 is the designation in both the SAE and AISI systems for this material. T11307 is the UNS number.

The properties of SAE-AISI M7 steel include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare SAE-AISI M7 steel to: tool steels (top), all iron alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.

Mechanical Properties

Elastic (Young's, Tensile) Modulus

200 GPa 29 x 106 psi

Poisson's Ratio


Shear Modulus

77 GPa 11 x 106 psi

Tensile Strength: Ultimate (UTS)

760 to 2210 MPa 110 to 320 x 103 psi

Thermal Properties

Latent Heat of Fusion

270 J/g

Melting Completion (Liquidus)

1560 °C 2830 °F

Melting Onset (Solidus)

1510 °C 2750 °F

Specific Heat Capacity

450 J/kg-K 0.11 BTU/lb-°F

Thermal Conductivity

28 W/m-K 16 BTU/h-ft-°F

Thermal Expansion

12 µm/m-K

Otherwise Unclassified Properties

Base Metal Price

18 % relative


8.1 g/cm3 500 lb/ft3

Embodied Carbon

8.9 kg CO2/kg material

Embodied Energy

130 MJ/kg 56 x 103 BTU/lb

Embodied Water

100 L/kg 12 gal/lb

Common Calculations

PREN (Pitting Resistance)


Stiffness to Weight: Axial

14 points

Stiffness to Weight: Bending

24 points

Strength to Weight: Axial

26 to 76 points

Strength to Weight: Bending

23 to 47 points

Thermal Diffusivity

7.8 mm2/s

Thermal Shock Resistance

24 to 69 points

Alloy Composition

Iron (Fe)Fe 79.8 to 83.8
Molybdenum (Mo)Mo 8.2 to 9.2
Chromium (Cr)Cr 3.5 to 4.0
Vanadium (V)V 1.8 to 2.3
Tungsten (W)W 1.4 to 2.1
Carbon (C)C 1.0 to 1.1
Silicon (Si)Si 0.2 to 0.55
Manganese (Mn)Mn 0.15 to 0.4
Nickel (Ni)Ni 0 to 0.3
Copper (Cu)Cu 0 to 0.25
Phosphorus (P)P 0 to 0.030
Sulfur (S)S 0 to 0.030

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

ASTM A600: Standard Specification for Tool Steel High Speed

Tool Steels, 5th ed., George Roberts et al., 1998

Tool Steels: Properties and Performance, Rafael A. Mesquita (editor), 2016

ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996