# Annealed A9 Tool Steel

Annealed SAE-AISI A9 is SAE-AISI A9 steel in the annealed condition. The graph bars on the material properties cards below compare annealed SAE-AISI A9 to: tool 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

230

Elastic (Young's, Tensile) Modulus

190 *GPa* 28 *x 10 ^{6} psi*

Elongation at Break

21 *%*

Fatigue Strength

250 *MPa* 37 *x 10 ^{3} psi*

Poisson's Ratio

0.29

Shear Modulus

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

Shear Strength

480 *MPa* 70 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

770 *MPa* 110 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

360 *MPa* 53 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

280 *J/g*

Melting Completion (Liquidus)

1460 *°C* 2650 *°F*

Melting Onset (Solidus)

1410 *°C* 2580 *°F*

Specific Heat Capacity

470 *J/kg-K* 0.11 *BTU/lb-°F*

Thermal Conductivity

35 *W/m-K* 20 *BTU/h-ft-°F*

Thermal Expansion

12 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

7.9 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

9.2 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

7.0 *% relative*

Density

7.8 *g/cm ^{3}* 480

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

70 *MJ/kg* 30 *x 10 ^{3} BTU/lb*

Embodied Water

82 *L/kg* 9.7 *gal/lb*

## Common Calculations

PREN (Pitting Resistance)

10

Resilience: Ultimate (Unit Rupture Work)

130 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

350 *kJ/m ^{3}*

Stiffness to Weight: Axial

14 *points*

Stiffness to Weight: Bending

25 *points*

Strength to Weight: Axial

28 *points*

Strength to Weight: Bending

24 *points*

Thermal Diffusivity

9.6 *mm ^{2}/s*

Thermal Shock Resistance

25 *points*

## Alloy Composition

Fe | 87 to 90.5 | |

Cr | 4.8 to 5.5 | |

Mo | 1.3 to 1.8 | |

Ni | 1.3 to 1.8 | |

V | 0.8 to 1.4 | |

Si | 1.0 to 1.2 | |

C | 0.45 to 0.55 | |

Mn | 0 to 0.5 | |

Cu | 0 to 0.25 | |

P | 0 to 0.030 | |

S | 0 to 0.030 |

All values are % weight. Ranges represent what is permitted under applicable standards.

## Followup Questions

## Further Reading

ASTM A681: Standard Specification for Tool Steels Alloy

Tool Steels, 5th ed., George Roberts et al., 1998

Tool Steels: Properties and Performance, Rafael A. Mesquita (editor), 2016

ASM Specialty Handbook: Carbon and Alloy Steels, J. R. Davis (editor), 1996