Stainless Steel 1.4515-AC vs 1.4515-ST
Stainless Steel · 1.4515 temper comparison
1.4515-AC and 1.4515-ST are two conditions of the same stainless steel grade, 1.4515: AC (spheroidize annealed) versus ST (solution annealed). The chemistry is identical, so every difference below comes from the condition. 1.4515-ST is the stronger of the two: yield strength 540 MPa (78.3 ksi) against 500 MPa (72.5 ksi) for 1.4515-AC, about 8% more; tensile strength follows at 740 MPa (107 ksi) vs 700 MPa (102 ksi). 1.4515-ST is the more ductile: elongation 25% versus 10% for 1.4515-AC, and 1.4515-AC is harder (255 HB vs 235 HB). 1.4515-ST runs hotter in service (280°C vs 150°C continuous). On the shop floor, 1.4515-ST welds better (good vs fair).
1.4515-STChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
1.4515-AC vs 1.4515-ST: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all stainless 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 stainless 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
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3
Physical
Density and transition temperatures.
Same in both: Density 7.75 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,465°C2,669 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 16 W/m·K9.2 BTU/hr·ft·°F · Specific Heat Capacity 480 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 270 J/g116 BTU/lb · Min Service Temperature -50°C-58 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.2 % IACS · Electrical Resistivity 8×10⁻⁷ Ω·m31.5 µΩ·in
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 65 / 100 · Brazeability / Solderability 30 / 100 · Polishability 65 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 5 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 80%
Strength versus weight
Yield strength against density for every stainless steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
1.4515-AC vs 1.4515-ST — frequently asked
Is 1.4515-ST stronger than 1.4515-AC?
Yes. 1.4515-ST has a typical yield strength of 540 MPa (78.3 ksi) against 500 MPa (72.5 ksi) for 1.4515-AC — about 8% more. Tensile strength is 740 MPa (107 ksi) vs 700 MPa (102 ksi).
Which condition does FabDigit quote by default, AC or ST?
ST is the default 1.4515 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, 1.4515-AC or 1.4515-ST?
1.4515-ST, by a small margin. Both rate poor for machinability — 28/100 against 22/100 for 1.4515-AC; for welding the order is 1.4515-ST first (good, 60/100) then 1.4515-AC (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4515-AC and 1.4515-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.