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Steel P355QH1 QT-100-150 vs P355QH1 QT-50-100

Steel · P355QH1 temper comparison

P355QH1 QT-100-150 and P355QH1 QT-50-100 are two conditions of the same steel grade, P355QH1: QT-100-150 (Q+T) versus QT-50-100 (Q+T). The chemistry is identical, so every difference below comes from the condition. P355QH1 QT-50-100 is the stronger of the two: yield strength 380 MPa (55.1 ksi) against 355 MPa (51.5 ksi) for P355QH1 QT-100-150, about 7% more. P355QH1 QT-50-100 is harder — 177 HV against 168 HV for P355QH1 QT-100-150 — which matters for wear surfaces and threads.

P355QH1 QT-50-100Choose it when strength drives the design, or when surface hardness matters.

P355QH1 QT-100-150 vs P355QH1 QT-50-100: properties

P355QH1 QT-100-150P355QH1 QT-50-100

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

520 MPa75.4 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

355 MPa51.5 ksi
380 MPa55.1 ksi

Reduction in Area

53%
55%

Compressive Strength

355 MPa51.5 ksi
380 MPa55.1 ksi

Shear Strength

340 MPa49.3 ksi
355 MPa51.5 ksi

Fatigue Strength (Endurance Limit)

230 MPa33.4 ksi
240 MPa34.8 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
140 MPa·√m127 ksi·√in

Charpy V-Notch Impact (RT)

120 J88.5 ft·lbf
150 J111 ft·lbf

Hardness, Brinell

160 HB
168 HB

Hardness, Rockwell B

83 HRB
85 HRB

Hardness, Vickers

168 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 · Elongation at Break 24%

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

58 / 100
57 / 100

Machinability Rating (AISI 1212 = 100 %)

64%
62%

Weldability

65 / 100
70 / 100

Formability (cold)

48 / 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-100-150 vs P355QH1 QT-50-100 — frequently asked

Is P355QH1 QT-50-100 stronger than P355QH1 QT-100-150?

Yes. P355QH1 QT-50-100 has a typical yield strength of 380 MPa (55.1 ksi) against 355 MPa (51.5 ksi) for P355QH1 QT-100-150 — about 7% more. Tensile strength is 540 MPa (78.3 ksi) vs 520 MPa (75.4 ksi).

Which condition does FabDigit quote by default, QT-100-150 or QT-50-100?

QT is the default P355QH1 condition in the FabDigit quote flow (neither QT-100-150 nor QT-50-100). 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-100-150 or P355QH1 QT-50-100?

P355QH1 QT-50-100. Its weldability rates very good (70/100) against good (65/100) for P355QH1 QT-100-150.

Ready to make it?

Upload a CAD file and FabDigit prices the part in P355QH1 QT-100-150 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.