SAE-AISI H25 (T20825) Tungsten Hot-Work Steel

SAE-AISI H25 steel is a tool steel. H25 is the designation in both the SAE and AISI systems for this material. T20825 is the UNS number.

The properties of SAE-AISI H25 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 H25 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 H25 Tool Steel Hardened H25 Tool Steel

Mechanical Properties

Elastic (Young's, Tensile) Modulus

200 GPa 29 x 10⁶ psi

Poisson's Ratio

0.29

Shear Modulus

79 GPa 11 x 10⁶ psi

Tensile Strength: Ultimate (UTS)

710 to 1620 MPa 100 to 240 x 10³ psi

Thermal Properties

Latent Heat of Fusion

250 J/g

Melting Completion (Liquidus)

1750 °C 3180 °F

Melting Onset (Solidus)

1700 °C 3090 °F

Specific Heat Capacity

420 J/kg-K 0.1 BTU/lb-°F

Thermal Conductivity

26 W/m-K 15 BTU/h-ft-°F

Thermal Expansion

12 µm/m-K

Otherwise Unclassified Properties

Base Metal Price

38 % relative

Density

9.1 g/cm³ 570 lb/ft³

Embodied Carbon

6.2 kg CO₂/kg material

Embodied Energy

93 MJ/kg 40 x 10³ BTU/lb

Embodied Water

83 L/kg 9.9 gal/lb

Common Calculations

PREN (Pitting Resistance)

Stiffness to Weight: Axial

12 points

Stiffness to Weight: Bending

22 points

Strength to Weight: Axial

22 to 50 points

Strength to Weight: Bending

20 to 34 points

Thermal Diffusivity

6.7 mm²/s

Thermal Shock Resistance

22 to 49 points

Alloy Composition

Iron (Fe)Fe		77.2 to 81.3
Tungsten (W)W		14 to 16
Chromium (Cr)Cr		3.8 to 4.5
Vanadium (V)V		0.4 to 0.6
Manganese (Mn)Mn		0.15 to 0.4
Silicon (Si)Si		0.15 to 0.4
Carbon (C)C		0.22 to 0.32
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