EN 1.7218 (25CrMo4) Chromium-Molybdenum Steel
EN 1.7218 steel is an alloy steel formulated for primary forming into wrought products. 1.7218 is the EN numeric designation for this material. 25CrMo4 is the EN chemical designation.
The properties of EN 1.7218 steel include six common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare EN 1.7218 steel to: EN wrought alloy 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
Brinell Hardness
150 to 230
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Tensile Strength: Ultimate (UTS)
500 to 1550 MPa 72 to 230 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 800 °F
Melting Completion (Liquidus)
1460 °C 2660 °F
Melting Onset (Solidus)
1420 °C 2590 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
44 W/m-K 26 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.5 % IACS
Otherwise Unclassified Properties
Base Metal Price
2.6 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.5 kg CO2/kg material
Embodied Energy
20 MJ/kg 8.6 x 103 BTU/lb
Embodied Water
52 L/kg 6.2 gal/lb
Common Calculations
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
18 to 55 points
Strength to Weight: Bending
18 to 38 points
Thermal Diffusivity
12 mm2/s
Thermal Shock Resistance
15 to 46 points
Alloy Composition
Among alloy steels, the composition of EN 1.7218 steel is notable for including aluminum (Al) and copper (Cu). Aluminum is used to control grain size and to deoxidize. Deoxidizing is required to control the effects of some other alloying elements. Copper is used to improve corrosion resistance, and to add at least some degree of precipitation hardenability.
| Fe | 96.2 to 98.1 | |
| Cr | 0.9 to 1.2 | |
| Mn | 0.6 to 0.9 | |
| C | 0.22 to 0.29 | |
| Mo | 0.15 to 0.3 | |
| Si | 0 to 0.4 | |
| Ni | 0 to 0.3 | |
| Cu | 0 to 0.3 | |
| Al | 0 to 0.040 | |
| P | 0 to 0.035 | |
| S | 0 to 0.035 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
EN 10216-2: Seamless steel tubes for pressure purposes - Technical delivery conditions - Part 2: Non-alloy and alloy steel tubes with specified elevated temperature properties
EN 10297-1: Seamless circular steel tubes for mechanical and general engineering purposes - Technical delivery conditions - Part 1: Non-alloy and alloy steel tubes
EN 10250-3: Open die steel forgings for general engineering purposes - Part 3: Alloy special steels
EN 10269: Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties
EN 10263-4: Steel rod, bars and wire for cold heading and cold extrusion - Part 4: Technical delivery conditions for steels for quenching and tempering
Creep-Resistant Steels, Fujio Abe et al. (editors), 2008
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005