# 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 10 ^{6} psi*

Elongation at Break

22 *%*

Fatigue Strength

190 *MPa* 28 *x 10 ^{3} psi*

Poisson's Ratio

0.29

Shear Modulus

73 *GPa* 11 *x 10 ^{6} psi*

Shear Strength

320 *MPa* 46 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

500 *MPa* 73 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

270 *MPa* 40 *x 10 ^{3} 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/cm ^{3}* 490

*lb/ft*

^{3}Embodied Carbon

1.4 *kg CO _{2}/kg material*

Embodied Energy

18 *MJ/kg* 7.9 *x 10 ^{3} BTU/lb*

Embodied Water

45 *L/kg* 5.4 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

95 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

200 *kJ/m ^{3}*

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 *mm ^{2}/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