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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


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


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

Iron (Fe)Fe 98.5 to 99
Carbon (C)C 0.72 to 0.85
Manganese (Mn)Mn 0.3 to 0.6
Sulfur (S)S 0 to 0.050
Phosphorus (P)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