Steel Ductile Iron Annealed vs Ductile Iron N&T
Steel · Ductile Iron temper comparison
Ductile Iron Annealed and Ductile Iron N&T are two conditions of the same steel grade, Ductile Iron: Annealed versus N&T (normalized and tempered). The chemistry is identical, so every difference below comes from the condition. Ductile Iron N&T is the stronger of the two: yield strength 510 MPa (74 ksi) against 300 MPa (43.5 ksi) for Ductile Iron Annealed, about 70% more; tensile strength follows at 730 MPa (106 ksi) vs 440 MPa (63.8 ksi). In exchange, Ductile Iron Annealed is the more ductile: elongation 20% versus 5% for Ductile Iron N&T, and Ductile Iron N&T is harder (260 HB vs 160 HB). Ductile Iron Annealed runs hotter in service (450°C vs 400°C continuous) and Ductile Iron Annealed conducts heat better (36 W/m·K vs 30 W/m·K). On the shop floor, Ductile Iron Annealed machines more easily (very good vs good) and Ductile Iron Annealed welds better (fair vs poor).
Ductile Iron AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
Ductile Iron N&TChoose it when strength drives the design.
Ductile Iron Annealed vs Ductile Iron N&T: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Ductile Iron AnnealedDuctile Iron N&T
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
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
Max Service Temperature (continuous)
Min Service Temperature
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
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.
Ductile Iron Annealed vs Ductile Iron N&T — frequently asked
Is Ductile Iron N&T stronger than Ductile Iron Annealed?
Yes. Ductile Iron N&T has a typical yield strength of 510 MPa (74 ksi) against 300 MPa (43.5 ksi) for Ductile Iron Annealed — about 70% more. Tensile strength is 730 MPa (106 ksi) vs 440 MPa (63.8 ksi).
Which condition does FabDigit quote by default, Annealed or N&T?
As Cast is the default Ductile Iron condition in the FabDigit quote flow (neither Annealed nor N&T). 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 N&T?
Ductile Iron Annealed. Its machinability rates very good (75/100) against good (55/100) for Ductile Iron N&T; for welding the order is Ductile Iron Annealed first (fair, 45/100) then Ductile Iron N&T (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in Ductile Iron Annealed and Ductile Iron N&T 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.