Hardened M42 Tool Steel
Hardened SAE-AISI M42 is SAE-AISI M42 steel in the hardened (H) condition. The graph bars on the material properties cards below compare hardened SAE-AISI M42 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
0.29
Rockwell C Hardness
71
Shear Modulus
78 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
2310 MPa 340 x 103 psi
Thermal Properties
Latent Heat of Fusion
270 J/g
Melting Completion (Liquidus)
1540 °C 2800 °F
Melting Onset (Solidus)
1490 °C 2710 °F
Specific Heat Capacity
450 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
20 W/m-K 11 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
30 % relative
Density
8.2 g/cm3 510 lb/ft3
Embodied Carbon
7.4 kg CO2/kg material
Embodied Energy
100 MJ/kg 44 x 103 BTU/lb
Embodied Water
140 L/kg 17 gal/lb
Common Calculations
PREN (Pitting Resistance)
38
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
79 points
Strength to Weight: Bending
48 points
Thermal Diffusivity
5.4 mm2/s
Thermal Shock Resistance
71 points
Alloy Composition
| Fe | 76.3 to 81 | |
| Mo | 9.0 to 10 | |
| Co | 7.8 to 8.8 | |
| Cr | 3.5 to 4.3 | |
| W | 1.2 to 1.9 | |
| V | 1.0 to 1.4 | |
| C | 1.1 to 1.2 | |
| Si | 0.15 to 0.65 | |
| 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
Sintering of Advanced Materials: Fundamentals and Processes, Zhigang Zak Fang (editor), 2010
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