SAE-AISI T8 (T12008) Tungsten High-Speed Steel

SAE-AISI T8 steel is a tool steel. T8 is the designation in both the SAE and AISI systems for this material. T12008 is the UNS number.

The properties of SAE-AISI T8 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 T8 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.

Annealed T8 Tool Steel Hardened T8 Tool Steel

Mechanical Properties

Elastic (Young's, Tensile) Modulus

200 GPa 29 x 10⁶ psi

Poisson's Ratio

0.29

Shear Modulus

78 GPa 11 x 10⁶ psi

Tensile Strength: Ultimate (UTS)

780 to 2140 MPa 110 to 310 x 10³ psi

Thermal Properties

Latent Heat of Fusion

250 J/g

Melting Completion (Liquidus)

1730 °C 3140 °F

Melting Onset (Solidus)

1670 °C 3050 °F

Specific Heat Capacity

420 J/kg-K 0.1 BTU/lb-°F

Thermal Conductivity

18 W/m-K 11 BTU/h-ft-°F

Thermal Expansion

12 µm/m-K

Otherwise Unclassified Properties

Base Metal Price

45 % relative

Density

9.0 g/cm³ 560 lb/ft³

Embodied Carbon

10 kg CO₂/kg material

Embodied Energy

160 MJ/kg 67 x 10³ BTU/lb

Embodied Water

120 L/kg 14 gal/lb

Common Calculations

PREN (Pitting Resistance)

Stiffness to Weight: Axial

12 points

Stiffness to Weight: Bending

22 points

Strength to Weight: Axial

24 to 66 points

Strength to Weight: Bending

21 to 41 points

Thermal Diffusivity

4.8 mm²/s

Thermal Shock Resistance

24 to 66 points

Alloy Composition

Iron (Fe)Fe		69.3 to 75.4
Tungsten (W)W		13.3 to 14.8
Cobalt (Co)Co		4.3 to 5.8
Chromium (Cr)Cr		3.8 to 4.5
Vanadium (V)V		1.8 to 2.4
Carbon (C)C		0.75 to 0.85
Molybdenum (Mo)Mo		0.4 to 1.0
Manganese (Mn)Mn		0.2 to 0.4
Silicon (Si)Si		0.2 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