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Steel P355QH-QT vs P355QH QT-50-100

Steel · P355QH temper comparison

P355QH-QT and P355QH QT-50-100 are two conditions of the same steel grade, P355QH: QT (quenched and tempered) versus QT-50-100 (QT). The chemistry is identical, so every difference below comes from the condition. P355QH-QT is the stronger of the two: yield strength 400 MPa (58 ksi) against 375 MPa (54.4 ksi) for P355QH QT-50-100, about 7% more.

P355QH-QTChoose it when strength drives the design.

P355QH-QT vs P355QH QT-50-100: properties

P355QH-QTP355QH QT-50-100

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

550 MPa79.8 ksi
530 MPa76.9 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
375 MPa54.4 ksi

Reduction in Area

55%
53%

Compressive Strength

400 MPa58 ksi
375 MPa54.4 ksi

Shear Strength

340 MPa49.3 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

270 MPa39.2 ksi
260 MPa37.7 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
115 MPa·√m105 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

175 HB
168 HB

Hardness, Rockwell B

88 HRB
85 HRB

Hardness, Vickers

185 HV
177 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.3 · Elongation at Break 25%

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,465°C2,669 °F · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.5 % IACS · Electrical Resistivity 2.3×10⁻⁷ Ω·m9.06 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

55 / 100
57 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
62%

Weldability

72 / 100
70 / 100

Formability (cold)

55 / 100
52 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 50 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 25%

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleP355QH

P355QH-QT vs P355QH QT-50-100 — frequently asked

Is P355QH-QT stronger than P355QH QT-50-100?

Yes. P355QH-QT has a typical yield strength of 400 MPa (58 ksi) against 375 MPa (54.4 ksi) for P355QH QT-50-100 — about 7% more. Tensile strength is 550 MPa (79.8 ksi) vs 530 MPa (76.9 ksi).

Which condition does FabDigit quote by default, QT or QT-50-100?

QT is the default P355QH 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.

When should I choose P355QH-QT over P355QH QT-50-100?

Pick P355QH-QT when strength drives the design.

Ready to make it?

Upload a CAD file and FabDigit prices the part in P355QH-QT and P355QH QT-50-100 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.