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ASTM A602 Grade M8501 (F20005) Cast Iron

Grade M8501 cast iron is automotive malleable cast iron in the quenched and tempered condition. M8501 is the ASTM designation for this material. F20005 is the UNS number. It has the highest strength and lowest ductility compared to the other variants of automotive malleable cast iron.

The graph bars on the material properties cards below compare grade M8501 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


Elastic (Young's, Tensile) Modulus

180 GPa 26 x 106 psi

Elongation at Break

1.0 %

Poisson's Ratio


Shear Modulus

70 GPa 10 x 106 psi

Tensile Strength: Ultimate (UTS)

720 MPa 110 x 103 psi

Tensile Strength: Yield (Proof)

590 MPa 85 x 103 psi

Thermal Properties

Latent Heat of Fusion

260 J/g

Melting Completion (Liquidus)

1410 °C 2570 °F

Melting Onset (Solidus)

1370 °C 2500 °F

Specific Heat Capacity

480 J/kg-K 0.12 BTU/lb-°F

Thermal Conductivity

41 W/m-K 24 BTU/h-ft-°F

Thermal Expansion

14 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

7.4 % IACS

Electrical Conductivity: Equal Weight (Specific)

8.7 % IACS

Otherwise Unclassified Properties

Base Metal Price

1.9 % relative


7.6 g/cm3 480 lb/ft3

Embodied Carbon

1.5 kg CO2/kg material

Embodied Energy

20 MJ/kg 8.7 x 103 BTU/lb

Embodied Water

45 L/kg 5.3 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

6.8 MJ/m3

Resilience: Unit (Modulus of Resilience)

950 kJ/m3

Stiffness to Weight: Axial

13 points

Stiffness to Weight: Bending

25 points

Strength to Weight: Axial

26 points

Strength to Weight: Bending

24 points

Thermal Diffusivity

11 mm2/s

Thermal Shock Resistance

21 points

Alloy Composition

Iron (Fe) 93.6 to 96.7
Carbon (C) 2.2 to 2.9
Silicon (Si) 0.9 to 1.9
Manganese (Mn) 0.15 to 1.3
Sulfur (S) 0.020 to 0.2
Phosphorus (P) 0.020 to 0.15

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

Followup Questions

Further Reading

ASTM A602: Standard Specification for Automotive Malleable Iron Castings

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

Properties and Selection: Irons, Steels and High Performance Alloys, ASM Handbook vol. 1, ASM International, 1993

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