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SAE-AISI T15 (T12015) Tungsten High-Speed Steel

SAE-AISI T15 steel is a tool steel. T15 is the designation in both the SAE and AISI systems for this material. T12015 is the UNS number. It has the highest embodied energy among the tool steels in the database.

The properties of SAE-AISI T15 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 T15 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

200 GPa 29 x 106 psi

Poisson's Ratio


Shear Modulus

76 GPa 11 x 106 psi

Tensile Strength: Ultimate (UTS)

830 to 2240 MPa 120 to 320 x 103 psi

Thermal Properties

Latent Heat of Fusion

250 J/g

Melting Completion (Liquidus)

1690 °C 3080 °F

Melting Onset (Solidus)

1640 °C 2990 °F

Specific Heat Capacity

430 J/kg-K 0.1 BTU/lb-°F

Thermal Conductivity

21 W/m-K 12 BTU/h-ft-°F

Thermal Expansion

12 µm/m-K

Otherwise Unclassified Properties

Base Metal Price

43 % relative


8.7 g/cm3 550 lb/ft3

Embodied Carbon

16 kg CO2/kg material

Embodied Energy

250 MJ/kg 110 x 103 BTU/lb

Embodied Water

140 L/kg 16 gal/lb

Common Calculations

PREN (Pitting Resistance)


Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

22 points

Strength to Weight: Axial

26 to 71 points

Strength to Weight: Bending

22 to 43 points

Thermal Diffusivity

5.6 mm2/s

Thermal Shock Resistance

26 to 70 points

Alloy Composition

Iron (Fe)Fe 67.5 to 73.5
Tungsten (W)W 11.8 to 13
Cobalt (Co)Co 4.8 to 5.3
Vanadium (V)V 4.5 to 5.3
Chromium (Cr)Cr 3.8 to 5.0
Carbon (C)C 1.5 to 1.6
Molybdenum (Mo)Mo 0 to 1.0
Manganese (Mn)Mn 0.15 to 0.4
Silicon (Si)Si 0.15 to 0.4
Nickel (Ni)Ni 0 to 0.3
Copper (Cu)Cu 0 to 0.25
Phosphorus (P)P 0 to 0.030
Sulfur (S)S 0 to 0.030

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

Followup Questions

Similar Alloys

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