Hardened M4 Tool Steel
Hardened SAE-AISI M4 is SAE-AISI M4 steel in the hardened (H) condition. The graph bars on the material properties cards below compare hardened SAE-AISI M4 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 28 x 106 psi
Poisson's Ratio
0.29
Rockwell C Hardness
66
Shear Modulus
76 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
2150 MPa 310 x 103 psi
Thermal Properties
Latent Heat of Fusion
260 J/g
Melting Completion (Liquidus)
1610 °C 2930 °F
Melting Onset (Solidus)
1560 °C 2840 °F
Specific Heat Capacity
440 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
25 W/m-K 15 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
25 % relative
Density
8.3 g/cm3 520 lb/ft3
Embodied Carbon
14 kg CO2/kg material
Embodied Energy
210 MJ/kg 91 x 103 BTU/lb
Embodied Water
110 L/kg 13 gal/lb
Common Calculations
PREN (Pitting Resistance)
30
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
23 points
Strength to Weight: Axial
72 points
Strength to Weight: Bending
45 points
Thermal Diffusivity
6.9 mm2/s
Thermal Shock Resistance
68 points
Alloy Composition
| Fe | 75.9 to 81.4 | |
| W | 5.3 to 6.5 | |
| Mo | 4.3 to 5.5 | |
| Cr | 3.8 to 4.8 | |
| V | 3.8 to 4.5 | |
| C | 1.3 to 1.4 | |
| Si | 0.2 to 0.45 | |
| 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
SAE J437: Selection and Heat Treatment of Tool and Die Steels
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