Annealed M7 Tool Steel
Annealed SAE-AISI M7 is SAE-AISI M7 steel in the annealed condition. The graph bars on the material properties cards below compare annealed SAE-AISI M7 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
Brinell Hardness
230
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 MPa 110 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)
35
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
26 points
Strength to Weight: Bending
23 points
Thermal Diffusivity
7.8 mm2/s
Thermal Shock Resistance
24 points
Alloy Composition
| Fe | 79.8 to 83.8 | |
| Mo | 8.2 to 9.2 | |
| Cr | 3.5 to 4.0 | |
| V | 1.8 to 2.3 | |
| W | 1.4 to 2.1 | |
| C | 1.0 to 1.1 | |
| Si | 0.2 to 0.55 | |
| Mn | 0.15 to 0.4 | |
| Ni | 0 to 0.3 | |
| Cu | 0 to 0.25 | |
| P | 0 to 0.030 | |
| S | 0 to 0.030 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
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