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Steel Ductile Iron Annealed vs Ductile Iron As Cast

Steel · Ductile Iron temper comparison

Ductile Iron Annealed and Ductile Iron As Cast are two conditions of the same steel grade, Ductile Iron: Annealed versus As Cast. The chemistry is identical, so every difference below comes from the condition. Ductile Iron As Cast is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 300 MPa (43.5 ksi) for Ductile Iron Annealed, about 13% more; tensile strength follows at 480 MPa (69.6 ksi) vs 440 MPa (63.8 ksi). In exchange, Ductile Iron Annealed is the more ductile: elongation 20% versus 14% for Ductile Iron As Cast, and Ductile Iron As Cast is harder (187 HB vs 160 HB). Ductile Iron Annealed runs hotter in service (450°C vs 400°C continuous). On the shop floor, Ductile Iron Annealed welds better (45 vs 35 out of 100).

Ductile Iron AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

Ductile Iron As CastChoose it when strength drives the design.

Ductile Iron Annealed vs Ductile Iron As Cast: properties

Ductile Iron AnnealedDuctile Iron As Cast

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

440 MPa63.8 ksi
480 MPa69.6 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
340 MPa49.3 ksi

Elongation at Break

20%
14%

Shear Strength

400 MPa58 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

205 MPa29.7 ksi
230 MPa33.4 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
42 MPa·√m38.2 ksi·√in

Charpy V-Notch Impact (RT)

14 J10.3 ft·lbf
10 J7.4 ft·lbf

Hardness, Brinell

160 HB
187 HB

Hardness, Rockwell B

84 HRB
90 HRB

Same in both: Elastic (Young's) Modulus 169 GPa24.5 Msi · Shear Modulus 65 GPa9.4 Msi · Bulk Modulus 130 GPa18.9 Msi · Poisson's Ratio 0.28 · Reduction in Area 12% · Compressive Strength 700 MPa102 ksi

Physical

Density and transition temperatures.

Same in both: Density 7.1 g/cm³0.26 lb/in³ · Melting Point (Solidus) 1,150°C2,102 °F · Liquidus Temperature 1,175°C2,147 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

36 W/m·K20.8 BTU/hr·ft·°F
33 W/m·K19.1 BTU/hr·ft·°F

Max Service Temperature (continuous)

450°C842 °F
400°C752 °F

Min Service Temperature

-50°C-58 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 220 J/g94.6 BTU/lb

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 3.1 % IACS · Electrical Resistivity 5.6×10⁻⁷ Ω·m22 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 16 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

75 / 100
68 / 100

Machinability Rating (AISI 1212 = 100 %)

80%
70%

Weldability

45 / 100
35 / 100

Same in both: Formability (cold) 8 / 100 · Castability 88 / 100 · Brazeability / Solderability 40 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 21 MJ/kg9,028 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 85%

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleDuctile Iron

Ductile Iron Annealed vs Ductile Iron As Cast — frequently asked

Is Ductile Iron As Cast stronger than Ductile Iron Annealed?

Yes. Ductile Iron As Cast has a typical yield strength of 340 MPa (49.3 ksi) against 300 MPa (43.5 ksi) for Ductile Iron Annealed — about 13% more. Tensile strength is 480 MPa (69.6 ksi) vs 440 MPa (63.8 ksi).

Which condition does FabDigit quote by default, Annealed or As Cast?

As Cast is the default Ductile Iron condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, Ductile Iron Annealed or Ductile Iron As Cast?

Ductile Iron Annealed. Its machinability rates very good (75/100) against good (68/100) for Ductile Iron As Cast; for welding the order is Ductile Iron Annealed first (fair, 45/100) then Ductile Iron As Cast (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in Ductile Iron Annealed and Ductile Iron As Cast side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.