Annealed S7 Tool Steel
Annealed SAE-AISI S7 is SAE-AISI S7 steel in the annealed condition. The graph bars on the material properties cards below compare annealed SAE-AISI S7 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
200
Elastic (Young's, Tensile) Modulus
190 GPa 28 x 106 psi
Elongation at Break
21 %
Fatigue Strength
250 MPa 37 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
74 GPa 11 x 106 psi
Shear Strength
420 MPa 61 x 103 psi
Tensile Strength: Ultimate (UTS)
670 MPa 97 x 103 psi
Tensile Strength: Yield (Proof)
370 MPa 53 x 103 psi
Thermal Properties
Latent Heat of Fusion
260 J/g
Melting Completion (Liquidus)
1460 °C 2660 °F
Melting Onset (Solidus)
1420 °C 2590 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
40 W/m-K 23 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.8 % IACS
Electrical Conductivity: Equal Weight (Specific)
9.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
5.0 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
2.3 kg CO2/kg material
Embodied Energy
31 MJ/kg 13 x 103 BTU/lb
Embodied Water
65 L/kg 7.8 gal/lb
Common Calculations
PREN (Pitting Resistance)
8.4
Resilience: Ultimate (Unit Rupture Work)
120 MJ/m3
Resilience: Unit (Modulus of Resilience)
350 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
24 points
Strength to Weight: Bending
22 points
Thermal Diffusivity
11 mm2/s
Thermal Shock Resistance
22 points
Alloy Composition
| Fe | 91.6 to 94.9 | |
| Cr | 3.0 to 3.5 | |
| Mo | 1.3 to 1.8 | |
| Si | 0.2 to 1.0 | |
| Mn | 0.2 to 0.9 | |
| C | 0.45 to 0.55 | |
| V | 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