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Stainless Steel 1.4125-QT150 vs 1.4125-QT500

Stainless Steel · 1.4125 temper comparison

1.4125-QT150 and 1.4125-QT500 are two conditions of the same stainless steel grade, 1.4125: QT150 (hardened, tempered 150–200 °C) versus QT500 (hardened, tempered 450–550 °C). The chemistry is identical, so every difference below comes from the condition. 1.4125-QT150 is the stronger of the two: yield strength 1,930 MPa (280 ksi) against 1,650 MPa (239 ksi) for 1.4125-QT500, about 17% more; tensile strength follows at 2,030 MPa (294 ksi) vs 1,800 MPa (261 ksi). In exchange, 1.4125-QT500 is the more ductile: elongation 3% versus 2% for 1.4125-QT150, and 1.4125-QT500 is harder (540 HB vs 250 HB). 1.4125-QT500 runs hotter in service (420°C vs 200°C continuous). On the shop floor, 1.4125-QT150 welds better (poor vs not recommended).

1.4125-QT150Choose it when strength drives the design, or when it will be welded.

1.4125-QT500Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

1.4125-QT150 vs 1.4125-QT500: properties

1.4125-QT1501.4125-QT500

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

2,030 MPa294 ksi
1,800 MPa261 ksi

Yield Strength (0.2% offset)

1,930 MPa280 ksi
1,650 MPa239 ksi

Elongation at Break

2%
3%

Reduction in Area

25%
8%

Shear Strength

460 MPa66.7 ksi
1,080 MPa157 ksi

Fatigue Strength (Endurance Limit)

550 MPa79.8 ksi
760 MPa110 ksi

Hardness, Brinell

250 HB
540 HB

Hardness, Vickers

680 HV
578 HV

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 0.28 · Charpy V-Notch Impact (RT) 6 J4.4 ft·lbf · Hardness, Rockwell B 99 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,370°C2,498 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

24 W/m·K13.9 BTU/hr·ft·°F
23 W/m·K13.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
420°C788 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.2 µm/m·K5.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.9 % IACS
2.7 % IACS

Electrical Resistivity

6×10⁻⁷ Ω·m23.6 µΩ·in
6.4×10⁻⁷ Ω·m25.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

46 / 100
28 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.3 V

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

6 / 100
10 / 100

Machinability Rating (AISI 1212 = 100 %)

40%
10%

Weldability

15 / 100
5 / 100

Formability (cold)

25 / 100
5 / 100

Polishability

90 / 100
60 / 100

Same in both: Castability 35 / 100 · Brazeability / Solderability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 55 MJ/kg23,646 BTU/lb · Embodied Carbon (primary production) 5.2 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 60%

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.

3005007001,0001,5002,0007.27.47.67.888.2Density (g/cm³)Yield strength (MPa) — log scale1.4125

1.4125-QT150 vs 1.4125-QT500 — frequently asked

Is 1.4125-QT150 stronger than 1.4125-QT500?

Yes. 1.4125-QT150 has a typical yield strength of 1,930 MPa (280 ksi) against 1,650 MPa (239 ksi) for 1.4125-QT500 — about 17% more. Tensile strength is 2,030 MPa (294 ksi) vs 1,800 MPa (261 ksi).

Which condition does FabDigit quote by default, QT150 or QT500?

+A is the default 1.4125 condition in the FabDigit quote flow (neither QT150 nor QT500). 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, 1.4125-QT150 or 1.4125-QT500?

1.4125-QT150. Its weldability rates poor (15/100) against not recommended (5/100) for 1.4125-QT500.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.4125-QT150 and 1.4125-QT500 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.