Stainless Steel 1.4307 +AT vs 1.4307 +CP350
Stainless Steel · 1.4307 temper comparison
1.4307 +AT and 1.4307 +CP350 are two conditions of the same stainless steel grade, 1.4307: +AT (solution annealed) versus +CP350 (cold worked to minimum 0.2 % proof strength 350 MPa). The chemistry is identical, so every difference below comes from the condition. 1.4307 +CP350 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 290 MPa (42.1 ksi) for 1.4307 +AT, about 45% more; tensile strength follows at 650 MPa (94.3 ksi) vs 580 MPa (84.1 ksi). In exchange, 1.4307 +AT is the more ductile: elongation 55% versus 30% for 1.4307 +CP350, and 1.4307 +CP350 is harder (200 HB vs 150 HB). 1.4307 +AT runs hotter in service (425°C vs 350°C continuous). On the shop floor, 1.4307 +CP350 machines more easily (48 vs 38 out of 100).
1.4307 +ATChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
1.4307 +CP350Choose it when strength drives the design, or when the part is machined in volume.
1.4307 +AT vs 1.4307 +CP350: 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.
Elastic (Young's) Modulus
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, Vickers
Same in both: Shear Modulus 77 GPa11.2 Msi · Bulk Modulus 145 GPa21 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.9 g/cm³0.29 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °F · Liquidus Temperature 1,450°C2,642 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 15 W/m·K8.7 BTU/hr·ft·°F · Specific Heat Capacity 500 J/kg·K0.12 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 16 µm/m·K8.9 µin/in·°F · Latent Heat of Fusion 285 J/g123 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 2.4 % IACS
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.05 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: Brazeability / Solderability 65 / 100 · Polishability 85 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 65%
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.
1.4307 +AT vs 1.4307 +CP350 — frequently asked
Is 1.4307 +CP350 stronger than 1.4307 +AT?
Yes. 1.4307 +CP350 has a typical yield strength of 420 MPa (60.9 ksi) against 290 MPa (42.1 ksi) for 1.4307 +AT — about 45% more. Tensile strength is 650 MPa (94.3 ksi) vs 580 MPa (84.1 ksi).
Which condition does FabDigit quote by default, +AT or +CP350?
+AT is the default 1.4307 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, 1.4307 +AT or 1.4307 +CP350?
1.4307 +CP350, by a small margin. Both rate fair for machinability — 48/100 against 38/100 for 1.4307 +AT; for welding the order is 1.4307 +AT first (excellent, 95/100) then 1.4307 +CP350 (excellent, 90/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4307 +AT and 1.4307 +CP350 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.