Ductile (Nodular, Spheroidal) Cast Iron
Ductile cast iron is a cast iron.
The properties of ductile 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 ductile 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 310
Elastic (Young's, Tensile) Modulus
170 to 180 GPa 24 to 26 x 106 psi
Elongation at Break
2.1 to 20 %
Fracture Toughness
14 to 30 MPa-m1/2 13 to 27 x 103 psi-in1/2
Poisson's Ratio
0.28 to 0.31
Shear Modulus
64 to 70 GPa 9.3 to 10 x 106 psi
Shear Strength
420 to 800 MPa 60 to 120 x 103 psi
Tensile Strength: Ultimate (UTS)
460 to 920 MPa 66 to 130 x 103 psi
Tensile Strength: Yield (Proof)
310 to 670 MPa 45 to 98 x 103 psi
Thermal Properties
Latent Heat of Fusion
270 J/g
Maximum Temperature: Mechanical
290 °C 550 °F
Melting Completion (Liquidus)
1160 °C 2120 °F
Melting Onset (Solidus)
1120 °C 2050 °F
Specific Heat Capacity
490 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
31 to 36 W/m-K 18 to 21 BTU/h-ft-°F
Thermal Expansion
11 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
7.4 % IACS
Electrical Conductivity: Equal Weight (Specific)
8.8 to 9.4 % IACS
Otherwise Unclassified Properties
Base Metal Price
1.9 % relative
Density
7.1 to 7.5 g/cm3 440 to 470 lb/ft3
Embodied Carbon
1.5 kg CO2/kg material
Embodied Energy
21 MJ/kg 8.9 x 103 BTU/lb
Embodied Water
43 L/kg 5.1 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
17 to 80 MJ/m3
Resilience: Unit (Modulus of Resilience)
280 to 1330 kJ/m3
Stiffness to Weight: Axial
12 to 14 points
Stiffness to Weight: Bending
24 to 26 points
Strength to Weight: Axial
17 to 35 points
Strength to Weight: Bending
18 to 29 points
Thermal Diffusivity
8.9 to 10 mm2/s
Thermal Shock Resistance
17 to 35 points
Alloy Composition
Fe | 93.7 to 95.5 | |
C | 3.0 to 3.5 | |
Si | 1.5 to 2.8 | |
P | 0 to 0.080 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
SAE J434: Automotive Ductile (Nodular) Iron Castings
ISO 1083: Spheroidal Graphite Cast Irons - Classification
ASTM A536: Standard Specification for Ductile Iron Castings
ASTM A395: Standard Specification for Ferritic Ductile Iron Pressure-Retaining Castings for Use at Elevated Temperatures
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