SAE-AISI 4130 (SCM430, G41300) Cr-Mo Steel
SAE-AISI 4130 steel is an alloy steel formulated for primary forming into wrought products. 4130 is the designation in both the SAE and AISI systems for this material. G41300 is the UNS number.
The properties of SAE-AISI 4130 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 4130 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 300
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
13 to 26 %
Fatigue Strength
320 to 660 MPa 47 to 96 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
340 to 640 MPa 49 to 93 x 103 psi
Tensile Strength: Ultimate (UTS)
530 to 1040 MPa 77 to 150 x 103 psi
Tensile Strength: Yield (Proof)
440 to 980 MPa 63 to 140 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
420 °C 790 °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
43 W/m-K 25 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.2 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.3 % 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 8.4 x 103 BTU/lb
Embodied Water
50 L/kg 6.0 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
83 to 180 MJ/m3
Resilience: Unit (Modulus of Resilience)
500 to 2550 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
19 to 37 points
Strength to Weight: Bending
19 to 29 points
Thermal Diffusivity
12 mm2/s
Thermal Shock Resistance
16 to 31 points
Alloy Composition
Among alloy steels, the composition of SAE-AISI 4130 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 | 97.3 to 98.2 | |
| Cr | 0.8 to 1.1 | |
| Mn | 0.4 to 0.6 | |
| C | 0.28 to 0.33 | |
| 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