Hardened A7 Tool Steel
Hardened SAE-AISI A7 is SAE-AISI A7 steel in the hardened (H) condition. The graph bars on the material properties cards below compare hardened SAE-AISI A7 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
190 GPa 27 x 106 psi
Poisson's Ratio
0.29
Rockwell C Hardness
66
Shear Modulus
72 GPa 10 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)
1470 °C 2680 °F
Melting Onset (Solidus)
1430 °C 2600 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
37 W/m-K 21 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
10 % relative
Density
7.7 g/cm3 480 lb/ft3
Embodied Carbon
13 kg CO2/kg material
Embodied Energy
200 MJ/kg 85 x 103 BTU/lb
Embodied Water
100 L/kg 12 gal/lb
Common Calculations
PREN (Pitting Resistance)
11
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
77 points
Strength to Weight: Bending
48 points
Thermal Diffusivity
10 mm2/s
Thermal Shock Resistance
72 points
Alloy Composition
| Fe | 81.4 to 87.7 | |
| Cr | 5.0 to 5.8 | |
| V | 3.9 to 5.2 | |
| C | 2.0 to 2.9 | |
| Mo | 0.9 to 1.4 | |
| W | 0.5 to 1.5 | |
| Mn | 0 to 0.8 | |
| Si | 0 to 0.5 | |
| 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 A681: Standard Specification for Tool Steels Alloy
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
CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015