AISI W1 (T72301) Water-Hardening Steel

AISI W1 steel is a tool steel. W1 is the AISI designation for this material. T72301 is the UNS number. It has the highest thermal conductivity among the tool steels in the database.

The properties of AISI W1 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 AISI W1 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 W1 Tool Steel Hardened W1 Tool Steel

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)

590 to 2320 MPa 86 to 340 x 10³ psi

Thermal Properties

Latent Heat of Fusion

250 J/g

Melting Completion (Liquidus)

1450 °C 2640 °F

Melting Onset (Solidus)

1410 °C 2570 °F

Specific Heat Capacity

470 J/kg-K 0.11 BTU/lb-°F

Thermal Conductivity

48 W/m-K 28 BTU/h-ft-°F

Thermal Expansion

10 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

7.1 % IACS

Electrical Conductivity: Equal Weight (Specific)

8.2 % IACS

Otherwise Unclassified Properties

Base Metal Price

2.2 % relative

Density

7.8 g/cm³ 490 lb/ft³

Embodied Carbon

1.6 kg CO₂/kg material

Embodied Energy

21 MJ/kg 9.2 x 10³ BTU/lb

Embodied Water

47 L/kg 5.5 gal/lb

Common Calculations

Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

24 points

Strength to Weight: Axial

21 to 83 points

Strength to Weight: Bending

20 to 50 points

Thermal Diffusivity

13 mm²/s

Thermal Shock Resistance

22 to 85 points

Alloy Composition

Iron (Fe)Fe		96.4 to 98.9
Carbon (C)C		0.7 to 1.5
Manganese (Mn)Mn		0.35 to 0.73
Silicon (Si)Si		0.1 to 0.4
Nickel (Ni)Ni		0 to 0.2
Copper (Cu)Cu		0 to 0.2
Chromium (Cr)Cr		0 to 0.15
Tungsten (W)W		0 to 0.15
Molybdenum (Mo)Mo		0 to 0.1
Vanadium (V)V		0 to 0.1
Phosphorus (P)P		0 to 0.025
Sulfur (S)S		0 to 0.025