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Stainless Steel 1.4317-F vs 1.4317-QT780

Stainless Steel · 1.4317 temper comparison

1.4317-F and 1.4317-QT780 are two conditions of the same stainless steel grade, 1.4317: F (as fabricated) versus QT780. The chemistry is identical, so every difference below comes from the condition. 1.4317-F is the stronger of the two: yield strength 900 MPa (131 ksi) against 620 MPa (89.9 ksi) for 1.4317-QT780, about 45% more; tensile strength follows at 1,200 MPa (174 ksi) vs 830 MPa (120 ksi). In exchange, 1.4317-QT780 is the more ductile: elongation 18% versus 6% for 1.4317-F, and 1.4317-F is harder (400 HB vs 260 HB). 1.4317-QT780 runs hotter in service (450°C vs 250°C continuous). On the shop floor, 1.4317-QT780 machines more easily (fair vs poor) and 1.4317-QT780 welds better (very good vs fair).

1.4317-FChoose it when strength drives the design.

1.4317-QT780Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

1.4317-F vs 1.4317-QT780: properties

1.4317-F1.4317-QT780

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,200 MPa174 ksi
830 MPa120 ksi

Yield Strength (0.2% offset)

900 MPa131 ksi
620 MPa89.9 ksi

Elongation at Break

6%
18%

Reduction in Area

15%
55%

Compressive Strength

950 MPa138 ksi
640 MPa92.8 ksi

Shear Strength

720 MPa104 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

470 MPa68.2 ksi
380 MPa55.1 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
180 MPa·√m164 ksi·√in

Charpy V-Notch Impact (RT)

15 J11.1 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

400 HB
260 HB

Hardness, Rockwell C

43 HRC
25 HRC

Hardness, Vickers

420 HV
275 HV

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 7.7 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,400°C2,552 °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
25 W/m·K14.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

250°C482 °F
450°C842 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.5 µm/m·K5.8 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Min Service Temperature -100°C-148 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

2.8 % IACS
2.9 % IACS

Electrical Resistivity

6.2×10⁻⁷ Ω·m24.4 µΩ·in
6×10⁻⁷ Ω·m23.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

42 / 100
52 / 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

18 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

15%
40%

Weldability

40 / 100
70 / 100

Formability (cold)

5 / 100
15 / 100

Same in both: Castability 70 / 100 · Brazeability / Solderability 40 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 50 MJ/kg21,496 BTU/lb · Embodied Carbon (primary production) 3.6 kg CO₂/kg · Embodied Water 200 L/kg24 gal/lb · Typical Recycled Content 70%

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 scale1.4317

1.4317-F vs 1.4317-QT780 — frequently asked

Is 1.4317-F stronger than 1.4317-QT780?

Yes. 1.4317-F has a typical yield strength of 900 MPa (131 ksi) against 620 MPa (89.9 ksi) for 1.4317-QT780 — about 45% more. Tensile strength is 1,200 MPa (174 ksi) vs 830 MPa (120 ksi).

Which condition does FabDigit quote by default, F or QT780?

QT780 is the default 1.4317 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, 1.4317-F or 1.4317-QT780?

1.4317-QT780. Its machinability rates fair (40/100) against poor (18/100) for 1.4317-F; for welding the order is 1.4317-QT780 first (very good, 70/100) then 1.4317-F (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.4317-F and 1.4317-QT780 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.