S21800 Stainless Steel vs. AWS E308Mo

Both S21800 stainless steel and AWS E308Mo are iron alloys. They have 90% of their average alloy composition in common. There are 21 material properties with values for both materials. Properties with values for just one material (14, in this case) are not shown.

For each property being compared, the top bar is S21800 stainless steel and the bottom bar is AWS E308Mo.

UNS S21800 (Alloy 218) Stainless Steel AWS E308Mo (W30820) Weld Metal

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		190
Elastic (Young's, Tensile) Modulus, GPa		200

Elongation at Break, %		40
Elongation at Break, %		40

Poisson's Ratio		0.28
Poisson's Ratio		0.28

Shear Modulus, GPa		75
Shear Modulus, GPa		78

Tensile Strength: Ultimate (UTS), MPa		740
Tensile Strength: Ultimate (UTS), MPa		620

Thermal Properties

Latent Heat of Fusion, J/g		340
Latent Heat of Fusion, J/g		290

Melting Completion (Liquidus), °C		1360
Melting Completion (Liquidus), °C		1440

Melting Onset (Solidus), °C		1310
Melting Onset (Solidus), °C		1400

Specific Heat Capacity, J/kg-K		500
Specific Heat Capacity, J/kg-K		470

Thermal Expansion, µm/m-K		16
Thermal Expansion, µm/m-K		14

Otherwise Unclassified Properties

Base Metal Price, % relative		15
Base Metal Price, % relative		19

Density, g/cm³		7.5
Density, g/cm³		7.9

Embodied Carbon, kg CO₂/kg material		3.1
Embodied Carbon, kg CO₂/kg material		3.8

Embodied Energy, MJ/kg		45
Embodied Energy, MJ/kg		53

Embodied Water, L/kg		150
Embodied Water, L/kg		160

Common Calculations

PREN (Pitting Resistance)		19
PREN (Pitting Resistance)		28

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

Stiffness to Weight: Bending, points		26
Stiffness to Weight: Bending, points		25

Strength to Weight: Axial, points		27
Strength to Weight: Axial, points		22

Strength to Weight: Bending, points		24
Strength to Weight: Bending, points		20

Thermal Shock Resistance, points		17
Thermal Shock Resistance, points		16

Alloy Composition

Carbon (C), %		0 to 0.1
Carbon (C), %		0 to 0.080

Chromium (Cr), %		16 to 18
Chromium (Cr), %		18 to 21

Copper (Cu), %		0
Copper (Cu), %		0 to 0.75

Iron (Fe), %		59.1 to 65.4
Iron (Fe), %		59.6 to 70.5

Manganese (Mn), %		7.0 to 9.0
Manganese (Mn), %		0.5 to 2.5

Molybdenum (Mo), %		0
Molybdenum (Mo), %		2.0 to 3.0

Nickel (Ni), %		8.0 to 9.0
Nickel (Ni), %		9.0 to 12

Nitrogen (N), %		0.080 to 0.18
Nitrogen (N), %		0

Phosphorus (P), %		0 to 0.060
Phosphorus (P), %		0 to 0.040

Silicon (Si), %		3.5 to 4.5
Silicon (Si), %		0 to 1.0

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