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SAE-AISI A7 (T30107) Air-Hardening Steel

SAE-AISI A7 steel is a tool steel. A7 is the designation in both the SAE and AISI systems for this material. T30107 is the UNS number.

The properties of SAE-AISI A7 steel include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare SAE-AISI A7 steel 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

Shear Modulus

72 GPa 10 x 106 psi

Tensile Strength: Ultimate (UTS)

800 to 2150 MPa 120 to 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

29 to 77 points

Strength to Weight: Bending

25 to 48 points

Thermal Diffusivity

10 mm2/s

Thermal Shock Resistance

27 to 72 points

Alloy Composition

Iron (Fe) 81.4 to 87.7
Chromium (Cr) 5.0 to 5.8
Vanadium (V) 3.9 to 5.2
Carbon (C) 2.0 to 2.9
Molybdenum (Mo) 0.9 to 1.4
Tungsten (W) 0.5 to 1.5
Manganese (Mn) 0 to 0.8
Silicon (Si) 0 to 0.5
Nickel (Ni) 0 to 0.3
Copper (Cu) 0 to 0.25
Phosphorus (P) 0 to 0.030
Sulfur (S) 0 to 0.030

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

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