Stainless Steel 1.4594 +AT vs 1.4594-H900
Stainless Steel · 1.4594 temper comparison
1.4594 +AT and 1.4594-H900 are two conditions of the same stainless steel grade, 1.4594: +AT (solution annealed) versus H900 (aged 482 °C (900 °F) for 1 h, peak hardness). The chemistry is identical, so every difference below comes from the condition. 1.4594-H900 is the stronger of the two: yield strength 1,240 MPa (180 ksi) against 795 MPa (115 ksi) for 1.4594 +AT, about 56% more; tensile strength follows at 1,310 MPa (190 ksi) vs 965 MPa (140 ksi). 1.4594-H900 is harder — 390 HB against 285 HB for 1.4594 +AT — which matters for wear surfaces and threads. 1.4594 +AT runs hotter in service (350°C vs 300°C continuous). On the shop floor, 1.4594 +AT machines more easily (fair vs poor).
1.4594 +ATChoose it when the part sees heat, or when the part is machined in volume.
1.4594-H900Choose it when strength drives the design, or when surface hardness matters.
1.4594 +AT vs 1.4594-H900: 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
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
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 0.29 · Compressive Strength 800 MPa116 ksi · Hardness, Vickers 300 HV
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 1,440°C2,624 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 17 W/m·K9.8 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.6 µm/m·K5.9 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -100°C-148 °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) -0.25 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Same in both: Weldability 70 / 100 · Formability (cold) 45 / 100 · Brazeability / Solderability 45 / 100 · Polishability 80 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 4 kg CO₂/kg · Embodied Water 120 L/kg14.4 gal/lb · Typical Recycled Content 55%
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.
1.4594 +AT vs 1.4594-H900 — frequently asked
Is 1.4594-H900 stronger than 1.4594 +AT?
Yes. 1.4594-H900 has a typical yield strength of 1,240 MPa (180 ksi) against 795 MPa (115 ksi) for 1.4594 +AT — about 56% more. Tensile strength is 1,310 MPa (190 ksi) vs 965 MPa (140 ksi).
Which condition does FabDigit quote by default, +AT or H900?
+AT is the default 1.4594 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, 1.4594 +AT or 1.4594-H900?
1.4594 +AT. Its machinability rates fair (45/100) against poor (28/100) for 1.4594-H900.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 1.4594 +AT and 1.4594-H900 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.