# Annealed A8 Tool Steel

Annealed SAE-AISI A8 is SAE-AISI A8 steel in the annealed condition. The graph bars on the material properties cards below compare annealed SAE-AISI A8 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

210

Elastic (Young's, Tensile) Modulus

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

Elongation at Break

21 *%*

Fatigue Strength

230 *MPa* 34 *x 10 ^{3} psi*

Poisson's Ratio

0.29

Shear Modulus

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

Shear Strength

440 *MPa* 63 *x 10 ^{3} psi*

Tensile Strength: Ultimate (UTS)

700 *MPa* 100 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

330 *MPa* 48 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

270 *J/g*

Melting Completion (Liquidus)

1480 *°C* 2690 *°F*

Melting Onset (Solidus)

1430 *°C* 2610 *°F*

Specific Heat Capacity

470 *J/kg-K* 0.11 *BTU/lb-°F*

Thermal Conductivity

37 *W/m-K* 21 *BTU/h-ft-°F*

Thermal Expansion

12 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

8.3 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

9.5 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

8.5 *% relative*

Density

7.9 *g/cm ^{3}* 490

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

31 *MJ/kg* 13 *x 10 ^{3} BTU/lb*

Embodied Water

73 *L/kg* 8.8 *gal/lb*

## Common Calculations

PREN (Pitting Resistance)

12

Resilience: Ultimate (Unit Rupture Work)

120 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

290 *kJ/m ^{3}*

Stiffness to Weight: Axial

14 *points*

Stiffness to Weight: Bending

24 *points*

Strength to Weight: Axial

25 *points*

Strength to Weight: Bending

22 *points*

Thermal Diffusivity

9.9 *mm ^{2}/s*

Thermal Shock Resistance

22 *points*

## Alloy Composition

Fe | 88.5 to 91.9 | |

Cr | 4.8 to 5.5 | |

Mo | 1.2 to 1.7 | |

W | 1.0 to 1.5 | |

Si | 0.75 to 1.1 | |

C | 0.5 to 0.6 | |

Mn | 0 to 0.5 | |

Ni | 0 to 0.3 | |

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