Steel FDSiCr-ANN vs FDSiCr OT-HEAVY
Steel · FDSiCr temper comparison
FDSiCr-ANN and FDSiCr OT-HEAVY are two conditions of the same steel grade, FDSiCr: ANN (annealed) versus OT-HEAVY (OT heavy wire). The chemistry is identical, so every difference below comes from the condition. FDSiCr OT-HEAVY is the stronger of the two: yield strength 1,520 MPa (220 ksi) against 500 MPa (72.5 ksi) for FDSiCr-ANN, about 3.0 times as much; tensile strength follows at 1,720 MPa (249 ksi) vs 780 MPa (113 ksi). In exchange, FDSiCr-ANN is the more ductile: elongation 16% versus 8% for FDSiCr OT-HEAVY, and FDSiCr OT-HEAVY is harder (50 HRC vs 20 HRC). FDSiCr-ANN runs hotter in service (400°C vs 250°C continuous) and FDSiCr-ANN conducts electricity better (8 % IACS vs 7 % IACS). On the shop floor, FDSiCr-ANN machines more easily (fair vs poor) and FDSiCr-ANN welds better (fair vs poor).
FDSiCr-ANNChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
FDSiCr OT-HEAVYChoose it when strength drives the design.
FDSiCr-ANN vs FDSiCr OT-HEAVY: 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.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79.3 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.2 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 25%
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.
FDSiCr-ANN vs FDSiCr OT-HEAVY — frequently asked
Is FDSiCr OT-HEAVY stronger than FDSiCr-ANN?
Yes. FDSiCr OT-HEAVY has a typical yield strength of 1,520 MPa (220 ksi) against 500 MPa (72.5 ksi) for FDSiCr-ANN — about 3.0 times as much. Tensile strength is 1,720 MPa (249 ksi) vs 780 MPa (113 ksi).
Which condition does FabDigit quote by default, ANN or OT-HEAVY?
OT is the default FDSiCr condition in the FabDigit quote flow (neither ANN nor OT-HEAVY). 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, FDSiCr-ANN or FDSiCr OT-HEAVY?
FDSiCr-ANN. Its machinability rates fair (45/100) against poor (18/100) for FDSiCr OT-HEAVY; for welding the order is FDSiCr-ANN first (fair, 35/100) then FDSiCr OT-HEAVY (poor, 18/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in FDSiCr-ANN and FDSiCr OT-HEAVY 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.