Nickel Alloy Nimonic 115-AF vs Nimonic 115-ST
Nickel Alloy · Nimonic 115 temper comparison
Nimonic 115-AF and Nimonic 115-ST are two conditions of the same nickel alloy grade, Nimonic 115: AF (as-forged / as-hot-rolled) versus ST (solution annealed). The chemistry is identical, so every difference below comes from the condition. Nimonic 115-AF is the stronger of the two: yield strength 720 MPa (104 ksi) against 600 MPa (87 ksi) for Nimonic 115-ST, about 20% more; tensile strength follows at 1,100 MPa (160 ksi) vs 960 MPa (139 ksi). In exchange, Nimonic 115-ST is the more ductile: elongation 33% versus 20% for Nimonic 115-AF, and Nimonic 115-ST is harder (360 HB vs 300 HB). Nimonic 115-ST runs hotter in service (900°C vs 815°C continuous).
Nimonic 115-AFChoose it when strength drives the design.
Nimonic 115-STChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
Nimonic 115-AF vs Nimonic 115-ST: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all nickel alloy 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 nickel alloy 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.
Elastic (Young's) Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Shear Modulus 85 GPa12.3 Msi · Bulk Modulus 190 GPa27.6 Msi · Poisson's Ratio 0.31
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,290°C2,354 °F · Liquidus Temperature 1,360°C2,480 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 10.7 W/m·K6.2 BTU/hr·ft·°F · Specific Heat Capacity 448 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 290 J/g125 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.15 V
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: Castability 60 / 100 · Brazeability / Solderability 45 / 100 · Polishability 70 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 210 MJ/kg90,284 BTU/lb · Embodied Carbon (primary production) 15 kg CO₂/kg · Embodied Water 220 L/kg26.4 gal/lb · Typical Recycled Content 30%
Strength versus weight
Yield strength against density for every nickel alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Nimonic 115-AF vs Nimonic 115-ST — frequently asked
Is Nimonic 115-AF stronger than Nimonic 115-ST?
Yes. Nimonic 115-AF has a typical yield strength of 720 MPa (104 ksi) against 600 MPa (87 ksi) for Nimonic 115-ST — about 20% more. Tensile strength is 1,100 MPa (160 ksi) vs 960 MPa (139 ksi).
Which condition does FabDigit quote by default, AF or ST?
ST+A is the default Nimonic 115 condition in the FabDigit quote flow (neither AF nor ST). 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 welds better, Nimonic 115-AF or Nimonic 115-ST?
Nimonic 115-ST. Its weldability rates poor (15/100) against not recommended (10/100) for Nimonic 115-AF.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Nimonic 115-AF and Nimonic 115-ST 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.