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.

Annealed M7 Tool Steel Hardened M7 Tool Steel

Mechanical Properties

Elastic (Young's, Tensile) Modulus

200 GPa 29 x 10⁶ psi

Poisson's Ratio

0.29

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

Density

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