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EN 1.4911 (X8CrCoNiMo10-6) Stainless Steel

EN 1.4911 stainless steel is a martensitic stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the quenched and tempered condition. 1.4911 is the EN numeric designation for this material. X8CrCoNiMo10-6 is the EN chemical designation.

It has the highest base cost among wrought martensitic stainless steels. In addition, it has a fairly high embodied energy and a moderately low ductility.

The graph bars on the material properties cards below compare EN 1.4911 stainless steel to: wrought martensitic stainless 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.

Mechanical Properties

Elastic (Young's, Tensile) Modulus

200 GPa 28 x 106 psi

Elongation at Break

11 %

Fatigue Strength

530 MPa 77 x 103 psi

Poisson's Ratio


Shear Modulus

76 GPa 11 x 106 psi

Shear Strength

640 MPa 93 x 103 psi

Tensile Strength: Ultimate (UTS)

1070 MPa 160 x 103 psi

Tensile Strength: Yield (Proof)

970 MPa 140 x 103 psi

Thermal Properties

Latent Heat of Fusion

270 J/g

Maximum Temperature: Corrosion

430 °C 800 °F

Maximum Temperature: Mechanical

700 °C 1290 °F

Melting Completion (Liquidus)

1450 °C 2650 °F

Melting Onset (Solidus)

1410 °C 2570 °F

Specific Heat Capacity

470 J/kg-K 0.11 BTU/lb-°F

Thermal Conductivity

20 W/m-K 12 BTU/h-ft-°F

Thermal Expansion

11 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

2.7 % IACS

Electrical Conductivity: Equal Weight (Specific)

3.0 % IACS

Otherwise Unclassified Properties

Base Metal Price

20 % relative


7.9 g/cm3 490 lb/ft3

Embodied Carbon

3.4 kg CO2/kg material

Embodied Energy

49 MJ/kg 21 x 103 BTU/lb

Embodied Water

130 L/kg 15 gal/lb

Common Calculations

PREN (Pitting Resistance)


Resilience: Ultimate (Unit Rupture Work)

120 MJ/m3

Resilience: Unit (Modulus of Resilience)

2410 kJ/m3

Stiffness to Weight: Axial

14 points

Stiffness to Weight: Bending

25 points

Strength to Weight: Axial

38 points

Strength to Weight: Bending

30 points

Thermal Diffusivity

5.4 mm2/s

Thermal Shock Resistance

37 points

Alloy Composition

Among wrought stainless steels, the composition of EN 1.4911 stainless steel is notable for including cobalt (Co) and boron (B). Cobalt is used to improve mechanical strength at elevated temperatures. Boron is used to improve hardenability. It has a substantial effect when added in even tiny amounts. It can also facilitate sintering.

Iron (Fe)Fe 75.7 to 83.8
Chromium (Cr)Cr 9.8 to 11.2
Cobalt (Co)Co 5.0 to 7.0
Manganese (Mn)Mn 0.3 to 1.3
Molybdenum (Mo)Mo 0.5 to 1.0
Nickel (Ni)Ni 0.2 to 1.2
Silicon (Si)Si 0.1 to 0.8
Tungsten (W)W 0 to 0.7
Niobium (Nb)Nb 0.2 to 0.5
Vanadium (V)V 0.1 to 0.4
Carbon (C)C 0.050 to 0.12
Nitrogen (N)N 0 to 0.035
Phosphorus (P)P 0 to 0.025
Boron (B)B 0.0050 to 0.015
Sulfur (S)S 0 to 0.015

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

EN 10302: Creep resisting steels, nickel and cobalt alloys

Machining of Stainless Steels and Super Alloys: Traditional and Nontraditional Techniques, Helmi A. Youssef, 2016

Creep-Resistant Steels, Fujio Abe et al. (editors), 2008

Welding Metallurgy and Weldability of Stainless Steels, John C. Lippold and Damian J. Kotecki, 2005

EN 10088-1: Stainless steels - Part 1: List of stainless steels

Corrosion of Stainless Steels, A. John Sedriks, 1996

Advances in Stainless Steels, Baldev Raj et al. (editors), 2010

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015