EN 1.3538 (100CrMo7-4) Through-Hardening Bearing Steel
EN 1.3538 steel is an alloy steel formulated for primary forming into wrought products. 1.3538 is the EN numeric designation for this material. 100CrMo7-4 is the EN chemical designation.
It has a moderately low melting temperature among EN wrought alloy steels. In addition, it has a moderately high base cost and a moderately low thermal conductivity.
The properties of EN 1.3538 steel include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare EN 1.3538 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
200 to 220
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)
670 to 740 MPa 97 to 110 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
440 °C 830 °F
Melting Completion (Liquidus)
1450 °C 2640 °F
Melting Onset (Solidus)
1410 °C 2570 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
41 W/m-K 24 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
3.0 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.6 kg CO2/kg material
Embodied Energy
21 MJ/kg 9.2 x 103 BTU/lb
Embodied Water
56 L/kg 6.6 gal/lb
Common Calculations
PREN (Pitting Resistance)
3.3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
24 to 26 points
Strength to Weight: Bending
22 to 23 points
Thermal Diffusivity
11 mm2/s
Thermal Shock Resistance
20 to 22 points
Alloy Composition
Among alloy steels, the composition of EN 1.3538 steel is notable for containing a comparatively high amount of carbon (C). Carbon is used to increase strength at the cost of a decrease in formability.
| Fe | 96 to 97.2 | |
| Cr | 1.7 to 2.0 | |
| C | 0.93 to 1.1 | |
| Mn | 0.6 to 0.8 | |
| Mo | 0.4 to 0.5 | |
| Si | 0.15 to 0.35 | |
| Cu | 0 to 0.3 | |
| Al | 0 to 0.050 | |
| S | 0 to 0.030 | |
| P | 0 to 0.025 | |
| O | 0 to 0.0015 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ISO 683-17: Heat-treated steels, alloy steels and free-cutting steels - Part 17: Ball and roller bearing steels
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015