# ASTM Grade 50 or 350 (ISO 350, EN-JL 1060, F13501) Grey Cast Iron

Grade 50 cast iron is grey cast iron in the as-fabricated (no temper or treatment) condition. Grade 50 is the ASTM designation for this material. 350 is the ISO numeric designation. And F13501 is the UNS number. The graph bars on the material properties cards below compare grade 50 cast iron to: cast irons (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

260

Compressive (Crushing) Strength

1130 *MPa* 160 *x 10 ^{3} psi*

Elastic (Young's, Tensile) Modulus

180 *GPa* 26 *x 10 ^{6} psi*

Elongation at Break

9.6 *%*

Fatigue Strength

150 *MPa* 21 *x 10 ^{3} psi*

Fracture Toughness

20 *MPa-m ^{1/2}* 18

*x 10*

^{3}psi-in^{1/2}Poisson's Ratio

0.29

Shear Modulus

69 *GPa* 10 *x 10 ^{6} psi*

Shear Strength

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

Tensile Strength: Ultimate (UTS)

380 *MPa* 56 *x 10 ^{3} psi*

Tensile Strength: Yield (Proof)

230 *MPa* 33 *x 10 ^{3} psi*

## Thermal Properties

Latent Heat of Fusion

280 *J/g*

Melting Completion (Liquidus)

1380 *°C* 2510 *°F*

Melting Onset (Solidus)

1180 *°C* 2150 *°F*

Specific Heat Capacity

490 *J/kg-K* 0.12 *BTU/lb-°F*

Thermal Conductivity

46 *W/m-K* 27 *BTU/h-ft-°F*

Thermal Expansion

11 *µm/m-K*

## Electrical Properties

Electrical Conductivity: Equal Volume

7.4 *% IACS*

Electrical Conductivity: Equal Weight (Specific)

8.9 *% IACS*

## Otherwise Unclassified Properties

Base Metal Price

1.9 *% relative*

Density

7.5 *g/cm ^{3}* 470

*lb/ft*

^{3}Embodied Carbon

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

Embodied Energy

21 *MJ/kg* 9.1 *x 10 ^{3} BTU/lb*

Embodied Water

44 *L/kg* 5.2 *gal/lb*

## Common Calculations

Resilience: Ultimate (Unit Rupture Work)

32 *MJ/m ^{3}*

Resilience: Unit (Modulus of Resilience)

150 *kJ/m ^{3}*

Stiffness to Weight: Axial

13 *points*

Stiffness to Weight: Bending

25 *points*

Strength to Weight: Axial

14 *points*

Strength to Weight: Bending

16 *points*

Thermal Diffusivity

13 *mm ^{2}/s*

Thermal Shock Resistance

15 *points*

## Alloy Composition

Fe | 92.1 to 93.9 | |

C | 3.1 to 3.4 | |

Si | 2.5 to 2.8 | |

Mn | 0.5 to 0.7 | |

P | 0 to 0.9 | |

S | 0 to 0.15 |

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

## Followup Questions

## Further Reading

ISO 185: Grey Cast Irons - Classification

ASTM A48: Standard Specification for Gray Iron Castings

Cast Iron: Physical and Engineering Properties, Harold T. Angus, 1976

Microstructure of Steels and Cast Irons, Madeleine Durand-Charre, 2004

Ferrous Materials: Steel and Cast Iron, Hans Berns and Werner Theisen, 2008

CRC Materials Science and Engineering Handbook, 4th ed., James F. Shackelford et al. (editors), 2015