Automotive Grey Cast Iron
Automotive grey cast iron is a cast iron. It can have the lowest tensile strength among the cast irons in the database.
The properties of automotive grey cast iron include nine common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare automotive grey 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
160 to 280
Elastic (Young's, Tensile) Modulus
180 GPa 26 x 106 psi
Elongation at Break
9.6 to 14 %
Poisson's Ratio
0.29
Shear Modulus
69 to 70 GPa 10 x 106 psi
Tensile Strength: Ultimate (UTS)
140 to 290 MPa 20 to 43 x 103 psi
Tensile Strength: Yield (Proof)
94 to 200 MPa 14 to 30 x 103 psi
Thermal Properties
Latent Heat of Fusion
260 to 280 J/g
Melting Completion (Liquidus)
1380 to 1390 °C 2510 to 2540 °F
Melting Onset (Solidus)
1340 to 1350 °C 2440 to 2470 °F
Specific Heat Capacity
490 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
41 to 43 W/m-K 24 to 25 BTU/h-ft-°F
Thermal Expansion
12 to 14 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.4 to 7.6 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.8 to 9.1 % IACS
Otherwise Unclassified Properties
Base Metal Price
1.9 to 3.0 % relative
Density
7.5 to 7.6 g/cm3 470 lb/ft3
Embodied Carbon
1.5 to 1.7 kg CO2/kg material
Embodied Energy
21 to 24 MJ/kg 8.9 to 10 x 103 BTU/lb
Embodied Water
44 to 51 L/kg 5.2 to 6.1 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
18 to 25 MJ/m3
Resilience: Unit (Modulus of Resilience)
25 to 110 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
5.2 to 11 points
Strength to Weight: Bending
8.0 to 13 points
Thermal Diffusivity
11 to 12 mm2/s
Thermal Shock Resistance
4.2 to 8.6 points
Followup Questions
Further Reading
ASTM A159: Standard Specification for Automotive Gray Iron Castings
SAE J431: Automotive Gray 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