SAE-AISI 4150 (G41500) Cr-Mo Steel
SAE-AISI 4150 steel is an alloy steel formulated for primary forming into wrought products. 4150 is the designation in both the SAE and AISI systems for this material. G41500 is the UNS number.
The properties of SAE-AISI 4150 steel include four 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 SAE-AISI 4150 steel to: SAE-AISI wrought 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 380
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
12 to 20 %
Fatigue Strength
260 to 780 MPa 38 to 110 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
410 to 800 MPa 60 to 120 x 103 psi
Tensile Strength: Ultimate (UTS)
660 to 1310 MPa 96 to 190 x 103 psi
Tensile Strength: Yield (Proof)
380 to 1220 MPa 55 to 180 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 790 °F
Melting Completion (Liquidus)
1460 °C 2650 °F
Melting Onset (Solidus)
1420 °C 2580 °F
Specific Heat Capacity
470 J/kg-K 0.11 BTU/lb-°F
Thermal Conductivity
42 W/m-K 24 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.3 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.4 % IACS
Otherwise Unclassified Properties
Base Metal Price
2.4 % 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
51 L/kg 6.1 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
82 to 180 MJ/m3
Resilience: Unit (Modulus of Resilience)
380 to 3930 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
24 to 47 points
Strength to Weight: Bending
22 to 34 points
Thermal Diffusivity
11 mm2/s
Thermal Shock Resistance
19 to 39 points
Alloy Composition
Among alloy steels, the composition of SAE-AISI 4150 steel is notable for containing comparatively high amounts of chromium (Cr) and manganese (Mn). Chromium is used to improve corrosion resistance and most mechanical properties (particularly at higher temperatures). Manganese is used to improve hardenability, hot workability, and surface quality. There is some loss of ductility and weldability, however.
| Fe | 96.7 to 97.7 | |
| Cr | 0.8 to 1.1 | |
| Mn | 0.75 to 1.0 | |
| C | 0.48 to 0.53 | |
| Si | 0.15 to 0.35 | |
| Mo | 0.15 to 0.25 | |
| S | 0 to 0.040 | |
| P | 0 to 0.035 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A752: Standard Specification for General Requirements for Wire Rods and Coarse Round Wire, Alloy Steel
ASTM A322: Standard Specification for Steel Bars, Alloy, Standard Grades
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
Manufacture and Uses of Alloy Steels, Henry D. Hibbard, 2005
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015