SAE-AISI 1040 (S40C, G10400) Carbon Steel
SAE-AISI 1040 steel is a carbon (non-alloy) steel formulated for primary forming into wrought products. 1040 is the designation in both the SAE and AISI systems for this material. G10400 is the UNS number.
The properties of SAE-AISI 1040 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 SAE-AISI 1040 steel to: wrought carbon or non-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
160 to 180
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
13 to 20 %
Fatigue Strength
220 to 340 MPa 31 to 49 x 103 psi
Poisson's Ratio
0.29
Reduction in Area
40 to 45 %
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
350 to 390 MPa 51 to 56 x 103 psi
Tensile Strength: Ultimate (UTS)
570 to 640 MPa 82 to 93 x 103 psi
Tensile Strength: Yield (Proof)
320 to 530 MPa 46 to 77 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
400 °C 750 °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
51 W/m-K 29 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.0 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.0 % IACS
Otherwise Unclassified Properties
Base Metal Price
1.8 % relative
Density
7.8 g/cm3 490 lb/ft3
Embodied Carbon
1.4 kg CO2/kg material
Embodied Energy
18 MJ/kg 7.9 x 103 BTU/lb
Embodied Water
46 L/kg 5.5 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
79 to 96 MJ/m3
Resilience: Unit (Modulus of Resilience)
270 to 760 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
20 to 23 points
Strength to Weight: Bending
19 to 21 points
Thermal Diffusivity
14 mm2/s
Thermal Shock Resistance
18 to 20 points
Alloy Composition
| Fe | 98.6 to 99.03 | |
| Mn | 0.6 to 0.9 | |
| C | 0.37 to 0.44 | |
| S | 0 to 0.050 | |
| P | 0 to 0.040 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
Cold-Formed Steel Structures to the AISI Specification, Gregory J. Hancock et al., 2001
ASTM A29: Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements for
Carbon Steel Handbook, D. Gandy, 2007
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015