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Steel P355QH1-QT vs P355QH1 QT-50-100

Steel · P355QH1 temper comparison

P355QH1-QT and P355QH1 QT-50-100 are two conditions of the same steel grade, P355QH1: QT (quenched and tempered) versus QT-50-100 (Q+T). The chemistry is identical, so every difference below comes from the condition. P355QH1-QT is the stronger of the two: yield strength 400 MPa (58 ksi) against 380 MPa (55.1 ksi) for P355QH1 QT-50-100, about 5% more.

P355QH1-QTChoose it when strength drives the design.

P355QH1-QT vs P355QH1 QT-50-100: properties

P355QH1-QTP355QH1 QT-50-100

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

560 MPa81.2 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
380 MPa55.1 ksi

Elongation at Break

25%
24%

Reduction in Area

58%
55%

Compressive Strength

400 MPa58 ksi
380 MPa55.1 ksi

Shear Strength

370 MPa53.7 ksi
355 MPa51.5 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

150 MPa·√m137 ksi·√in
140 MPa·√m127 ksi·√in

Charpy V-Notch Impact (RT)

180 J133 ft·lbf
150 J111 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 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Same in both: Thermal Conductivity 45 W/m·K26 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 250 J/g107 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 9 % IACS · Electrical Resistivity 1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.65 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

75 / 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) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 60 L/kg7.2 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 scaleP355QH1

P355QH1-QT vs P355QH1 QT-50-100 — frequently asked

Is P355QH1-QT stronger than P355QH1 QT-50-100?

Yes. P355QH1-QT has a typical yield strength of 400 MPa (58 ksi) against 380 MPa (55.1 ksi) for P355QH1 QT-50-100 — about 5% more. Tensile strength is 560 MPa (81.2 ksi) vs 540 MPa (78.3 ksi).

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

QT is the default P355QH1 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 welds better, P355QH1-QT or P355QH1 QT-50-100?

P355QH1-QT. Its weldability rates very good (75/100) against very good (70/100) for P355QH1 QT-50-100.

Ready to make it?

Upload a CAD file and FabDigit prices the part in P355QH1-QT and P355QH1 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.