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SAE-AISI T6 (T12006) Tungsten High-Speed Steel

SAE-AISI T6 steel is a tool steel. T6 is the designation in both the SAE and AISI systems for this material. T12006 is the UNS number. It has the highest base cost among tool steels. In addition, it has the highest density and the highest melting temperature.

The properties of SAE-AISI T6 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 T6 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

210 GPa 30 x 106 psi

Poisson's Ratio


Shear Modulus

81 GPa 12 x 106 psi

Tensile Strength: Ultimate (UTS)

880 to 2150 MPa 130 to 310 x 103 psi

Thermal Properties

Latent Heat of Fusion

250 J/g

Melting Completion (Liquidus)

1830 °C 3320 °F

Melting Onset (Solidus)

1770 °C 3210 °F

Specific Heat Capacity

400 J/kg-K 0.1 BTU/lb-°F

Thermal Conductivity

18 W/m-K 10 BTU/h-ft-°F

Thermal Expansion

12 µm/m-K

Otherwise Unclassified Properties

Base Metal Price

70 % relative


9.5 g/cm3 600 lb/ft3

Embodied Carbon

11 kg CO2/kg material

Embodied Energy

170 MJ/kg 73 x 103 BTU/lb

Embodied Water

160 L/kg 20 gal/lb

Common Calculations

PREN (Pitting Resistance)


Stiffness to Weight: Axial

12 points

Stiffness to Weight: Bending

21 points

Strength to Weight: Axial

26 to 63 points

Strength to Weight: Bending

21 to 39 points

Thermal Diffusivity

4.7 mm2/s

Thermal Shock Resistance

26 to 64 points

Alloy Composition

Iron (Fe) 55.9 to 63.5
Tungsten (W) 18.5 to 21
Cobalt (Co) 11 to 13
Chromium (Cr) 4.0 to 4.8
Vanadium (V) 1.5 to 2.1
Carbon (C) 0.75 to 0.85
Molybdenum (Mo) 0.4 to 1.0
Manganese (Mn) 0.2 to 0.4
Silicon (Si) 0.2 to 0.4
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 A600: Standard Specification for Tool Steel High Speed

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