SAE-AISI O6 Steel vs. R30008 Cobalt

SAE-AISI O6 steel belongs to the iron alloys classification, while R30008 cobalt belongs to the cobalt alloys. There are 19 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.

For each property being compared, the top bar is SAE-AISI O6 steel and the bottom bar is R30008 cobalt.

SAE-AISI O6 (T31506) Oil-Hardening Steel UNS R30008 (ASTM F1058 Grade 2) Cobalt

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		180
Elastic (Young's, Tensile) Modulus, GPa		210

Poisson's Ratio		0.29
Poisson's Ratio		0.29

Shear Modulus, GPa		71
Shear Modulus, GPa		83

Tensile Strength: Ultimate (UTS), MPa		670 to 2070
Tensile Strength: Ultimate (UTS), MPa		950 to 1700

Thermal Properties

Latent Heat of Fusion, J/g		260
Latent Heat of Fusion, J/g		320

Melting Completion (Liquidus), °C		1430
Melting Completion (Liquidus), °C		1400

Melting Onset (Solidus), °C		1390
Melting Onset (Solidus), °C		1330

Specific Heat Capacity, J/kg-K		480
Specific Heat Capacity, J/kg-K		450

Thermal Expansion, µm/m-K		12
Thermal Expansion, µm/m-K		13

Otherwise Unclassified Properties

Base Metal Price, % relative		2.3
Base Metal Price, % relative		95

Density, g/cm³		7.7
Density, g/cm³		8.4

Embodied Carbon, kg CO₂/kg material		1.5
Embodied Carbon, kg CO₂/kg material		8.1

Embodied Energy, MJ/kg		21
Embodied Energy, MJ/kg		110

Embodied Water, L/kg		47
Embodied Water, L/kg		400

Common Calculations

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

Stiffness to Weight: Bending, points		25
Stiffness to Weight: Bending, points		24

Strength to Weight: Axial, points		24 to 74
Strength to Weight: Axial, points		31 to 56

Strength to Weight: Bending, points		22 to 47
Strength to Weight: Bending, points		25 to 37

Thermal Shock Resistance, points		22 to 69
Thermal Shock Resistance, points		25 to 44

Alloy Composition

Boron (B), %		0
Boron (B), %		0 to 0.0010

Carbon (C), %		1.3 to 1.6
Carbon (C), %		0 to 0.15

Chromium (Cr), %		0 to 0.3
Chromium (Cr), %		18.5 to 21.5

Cobalt (Co), %		0
Cobalt (Co), %		39 to 42

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

Iron (Fe), %		94.6 to 97.7
Iron (Fe), %		7.6 to 20

Manganese (Mn), %		0.3 to 1.1
Manganese (Mn), %		1.0 to 2.0

Molybdenum (Mo), %		0.2 to 0.3
Molybdenum (Mo), %		6.5 to 7.5

Nickel (Ni), %		0 to 0.3
Nickel (Ni), %		15 to 18

Phosphorus (P), %		0 to 0.030
Phosphorus (P), %		0 to 0.015

Silicon (Si), %		0.55 to 1.5
Silicon (Si), %		0 to 1.2

Sulfur (S), %		0 to 0.030
Sulfur (S), %		0 to 0.015

Comparable Variants

Annealed Condition