ASTM A897 Grade 3 (ASTM 175-125-4 or 1200-850-04, ISO 1200-3, EN-JS 1120) Cast Iron
ASTM A897 grade 3 is austempered cast iron in the heat treated (HT) condition. 175-125-4 is the ASTM designation for this material. 1200-3 is the ISO numeric designation. The graph bars on the material properties cards below compare ASTM A897 grade 3 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
390
Compressive (Crushing) Strength
1900 MPa 280 x 103 psi
Elastic (Young's, Tensile) Modulus
180 GPa 26 x 106 psi
Elongation at Break
4.2 %
Fracture Toughness
54 MPa-m1/2 49 x 103 psi-in1/2
Poisson's Ratio
0.29
Shear Modulus
63 GPa 9.1 x 106 psi
Shear Strength
1080 MPa 160 x 103 psi
Tensile Strength: Ultimate (UTS)
1320 MPa 190 x 103 psi
Tensile Strength: Yield (Proof)
940 MPa 140 x 103 psi
Thermal Properties
Latent Heat of Fusion
280 J/g
Melting Completion (Liquidus)
1380 °C 2520 °F
Melting Onset (Solidus)
1340 °C 2450 °F
Specific Heat Capacity
490 J/kg-K 0.12 BTU/lb-°F
Thermal Conductivity
42 W/m-K 24 BTU/h-ft-°F
Thermal Expansion
13 µm/m-K
Otherwise Unclassified Properties
Base Metal Price
2.9 % relative
Density
7.5 g/cm3 470 lb/ft3
Embodied Carbon
1.8 kg CO2/kg material
Embodied Energy
25 MJ/kg 11 x 103 BTU/lb
Embodied Water
48 L/kg 5.7 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
51 MJ/m3
Resilience: Unit (Modulus of Resilience)
2470 kJ/m3
Stiffness to Weight: Axial
13 points
Stiffness to Weight: Bending
25 points
Strength to Weight: Axial
49 points
Strength to Weight: Bending
36 points
Thermal Diffusivity
11 mm2/s
Thermal Shock Resistance
39 points
Alloy Composition
| Fe | 89.6 to 94 | |
| C | 3.4 to 3.8 | |
| Si | 2.3 to 2.7 | |
| Ni | 0 to 2.0 | |
| Cu | 0 to 0.8 | |
| Mn | 0.3 to 0.4 | |
| Mo | 0 to 0.3 | |
| Cr | 0 to 0.1 | |
| V | 0 to 0.1 | |
| Al | 0 to 0.050 | |
| P | 0 to 0.040 | |
| Mg | 0 to 0.040 | |
| Se | 0 to 0.030 | |
| S | 0 to 0.020 | |
| Sn | 0 to 0.020 | |
| As | 0 to 0.020 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Further Reading
ISO 17804: Founding - Ausferritic Spheroidal Graphite Cast Irons - Classification
ASTM A897: Standard Specification for Austempered Ductile Iron Castings
Cast Iron: Physical and Engineering Properties, Harold T. Angus, 1976
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