SAE-AISI 1078 (G10780) Carbon Steel
SAE-AISI 1078 steel is a carbon (non-alloy) steel formulated for primary forming into wrought products. 1078 is the designation in both the SAE and AISI systems for this material. G10780 is the UNS number.
It can have a moderately low ductility among wrought carbon or non-alloy steels. In addition, it can have a fairly high tensile strength and has a moderately low thermal conductivity.
The properties of SAE-AISI 1078 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 1078 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
220 to 230
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
11 to 14 %
Fatigue Strength
270 to 350 MPa 40 to 51 x 103 psi
Poisson's Ratio
0.29
Reduction in Area
34 to 45 %
Shear Modulus
72 GPa 10 x 106 psi
Shear Strength
440 to 470 MPa 64 to 68 x 103 psi
Tensile Strength: Ultimate (UTS)
730 to 780 MPa 110 x 103 psi
Tensile Strength: Yield (Proof)
430 to 570 MPa 62 to 82 x 103 psi
Thermal Properties
Latent Heat of Fusion
250 J/g
Maximum Temperature: Mechanical
400 °C 750 °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
49 W/m-K 28 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.0 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.1 % 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
45 L/kg 5.4 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
77 to 90 MJ/m3
Resilience: Unit (Modulus of Resilience)
490 to 860 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
26 to 28 points
Strength to Weight: Bending
23 to 24 points
Thermal Diffusivity
13 mm2/s
Thermal Shock Resistance
25 to 26 points
Alloy Composition
Fe | 98.5 to 99 | |
C | 0.72 to 0.85 | |
Mn | 0.3 to 0.6 | |
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
ASTM A29: Standard Specification for Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements for
Microstructure of Steels and Cast Irons, Madeleine Durand-Charre, 2004
Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook vol. 1, ASM International, 1993
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