ASTM A372 Grade A Carbon Steel
ASTM A372 grade A steel is a carbon (non-alloy) steel formulated for primary forming into wrought products. Cited properties are appropriate for the normalized condition. ASTM A372 Grade A is the ASTM designation for this material. Older literature may refer to this material as Type I, but this is now discouraged.
The graph bars on the material properties cards below compare ASTM A372 grade A 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
140
Elastic (Young's, Tensile) Modulus
190 GPa 27 x 106 psi
Elongation at Break
22 %
Fatigue Strength
190 MPa 28 x 103 psi
Poisson's Ratio
0.29
Shear Modulus
73 GPa 11 x 106 psi
Shear Strength
320 MPa 46 x 103 psi
Tensile Strength: Ultimate (UTS)
500 MPa 73 x 103 psi
Tensile Strength: Yield (Proof)
270 MPa 40 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
52 W/m-K 30 BTU/h-ft-°F
Thermal Expansion
12 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.1 % 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)
95 MJ/m3
Resilience: Unit (Modulus of Resilience)
200 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
24 points
Strength to Weight: Axial
18 points
Strength to Weight: Bending
18 points
Thermal Diffusivity
14 mm2/s
Thermal Shock Resistance
16 points
Alloy Composition
| Fe | 98.3 to 99.85 | |
| Mn | 0 to 1.0 | |
| Si | 0.15 to 0.35 | |
| C | 0 to 0.3 | |
| P | 0 to 0.015 | |
| S | 0 to 0.010 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM A372: Standard Specification for Carbon and Alloy Steel Forgings for Thin-Walled Pressure Vessels
Microstructure of Steels and Cast Irons, Madeleine Durand-Charre, 2004
Pressure Vessels: External Pressure Technology, 2nd ed., Carl T. F. Ross, 2011
Carbon Steel Handbook, D. Gandy, 2007
ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996
Steels: Processing, Structure, and Performance, 2nd ed., George Krauss, 2015