Stainless Steel S42300-QT590 vs S42300-QT650
Stainless Steel · S42300 temper comparison
S42300-QT590 and S42300-QT650 are two conditions of the same stainless steel grade, S42300: QT590 (Q&T 590 °C) versus QT650 (Q&T 650 °C). The chemistry is identical, so every difference below comes from the condition. S42300-QT590 is the stronger of the two: yield strength 1,000 MPa (145 ksi) against 850 MPa (123 ksi) for S42300-QT650, about 18% more; tensile strength follows at 1,170 MPa (170 ksi) vs 1,000 MPa (145 ksi). In exchange, S42300-QT650 is the more ductile: elongation 17% versus 14% for S42300-QT590, and S42300-QT590 is harder (341 HB vs 293 HB). S42300-QT650 runs hotter in service (540°C vs 480°C continuous).
S42300-QT590Choose it when strength drives the design.
S42300-QT650Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
S42300-QT590 vs S42300-QT650: 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
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 880 MPa128 ksi · Shear Strength 620 MPa89.9 ksi
Physical
Density and transition temperatures.
Same in both: Density 7.76 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,510°C2,750 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 24 W/m·K13.9 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.2 µm/m·K6.2 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.32 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 25 / 100 · Formability (cold) 20 / 100 · Brazeability / Solderability 40 / 100 · Polishability 72 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 53 MJ/kg22,786 BTU/lb · Embodied Carbon (primary production) 4.8 kg CO₂/kg · Embodied Water 130 L/kg15.6 gal/lb · Typical Recycled Content 45%
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.
S42300-QT590 vs S42300-QT650 — frequently asked
Is S42300-QT590 stronger than S42300-QT650?
Yes. S42300-QT590 has a typical yield strength of 1,000 MPa (145 ksi) against 850 MPa (123 ksi) for S42300-QT650 — about 18% more. Tensile strength is 1,170 MPa (170 ksi) vs 1,000 MPa (145 ksi).
Which condition does FabDigit quote by default, QT590 or QT650?
QT650 is the default S42300 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, S42300-QT590 or S42300-QT650?
S42300-QT650. Its machinability rates fair (38/100) against poor (30/100) for S42300-QT590.
Ready to make it?
Upload a CAD file and FabDigit prices the part in S42300-QT590 and S42300-QT650 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.