SAE-AISI H21 Steel vs. R30006 Cobalt

SAE-AISI H21 steel belongs to the iron alloys classification, while R30006 cobalt belongs to the cobalt alloys. There are 20 material properties with values for both materials. Properties with values for just one material (12, in this case) are not shown.

For each property being compared, the top bar is SAE-AISI H21 steel and the bottom bar is R30006 cobalt.

SAE-AISI H21 (T20821) Tungsten Hot-Work Steel UNS R30006 Co-Cr-W Alloy

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		200
Elastic (Young's, Tensile) Modulus, GPa		220

Poisson's Ratio		0.29
Poisson's Ratio		0.28

Shear Modulus, GPa		76
Shear Modulus, GPa		85

Tensile Strength: Ultimate (UTS), MPa		720 to 1790
Tensile Strength: Ultimate (UTS), MPa		900

Thermal Properties

Latent Heat of Fusion, J/g		250
Latent Heat of Fusion, J/g		320

Melting Completion (Liquidus), °C		1630
Melting Completion (Liquidus), °C		1400

Melting Onset (Solidus), °C		1580
Melting Onset (Solidus), °C		1290

Specific Heat Capacity, J/kg-K		440
Specific Heat Capacity, J/kg-K		450

Thermal Conductivity, W/m-K		27
Thermal Conductivity, W/m-K		15

Thermal Expansion, µm/m-K		11
Thermal Expansion, µm/m-K		11

Otherwise Unclassified Properties

Density, g/cm³		8.5
Density, g/cm³		8.6

Embodied Carbon, kg CO₂/kg material		4.5
Embodied Carbon, kg CO₂/kg material		7.8

Embodied Energy, MJ/kg		68
Embodied Energy, MJ/kg		110

Embodied Water, L/kg		72
Embodied Water, L/kg		500

Common Calculations

Stiffness to Weight: Axial, points		13
Stiffness to Weight: Axial, points		14

Stiffness to Weight: Bending, points		23
Stiffness to Weight: Bending, points		23

Strength to Weight: Axial, points		23 to 58
Strength to Weight: Axial, points		29

Strength to Weight: Bending, points		21 to 38
Strength to Weight: Bending, points		24

Thermal Diffusivity, mm²/s		7.1
Thermal Diffusivity, mm²/s		3.9

Thermal Shock Resistance, points		24 to 59
Thermal Shock Resistance, points		26

Alloy Composition

Carbon (C), %		0.28 to 0.36
Carbon (C), %		0.9 to 1.4

Chromium (Cr), %		3.0 to 3.8
Chromium (Cr), %		27 to 32

Cobalt (Co), %		0
Cobalt (Co), %		48.6 to 68.1

Copper (Cu), %		0 to 0.25
Copper (Cu), %		0

Iron (Fe), %		87.6 to 93.8
Iron (Fe), %		0 to 3.0

Manganese (Mn), %		0.15 to 0.4
Manganese (Mn), %		0

Molybdenum (Mo), %		0
Molybdenum (Mo), %		0 to 1.0

Nickel (Ni), %		0 to 0.3
Nickel (Ni), %		0 to 3.0

Phosphorus (P), %		0 to 0.030
Phosphorus (P), %		0

Silicon (Si), %		0.15 to 0.5
Silicon (Si), %		0 to 2.0

Sulfur (S), %		0 to 0.030
Sulfur (S), %		0

Tungsten (W), %		8.5 to 10
Tungsten (W), %		4.0 to 6.0

Vanadium (V), %		0.3 to 0.6
Vanadium (V), %		0