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Steel P690QH QT-100-150 vs P690QH QT-50-100

Steel · P690QH temper comparison

P690QH QT-100-150 and P690QH QT-50-100 are two conditions of the same steel grade, P690QH: QT-100-150 (QT) versus QT-50-100 (QT). The chemistry is identical, so every difference below comes from the condition. Both yield at about 680 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (QT versus QT). P690QH QT-50-100 is harder — 24 HRC against 22 HRC for P690QH QT-100-150 — which matters for wear surfaces and threads.

P690QH QT-50-100Choose it when surface hardness matters.

P690QH QT-100-150 vs P690QH QT-50-100: properties

P690QH QT-100-150P690QH QT-50-100

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

790 MPa115 ksi
820 MPa119 ksi

Yield Strength (0.2% offset)

680 MPa98.6 ksi
700 MPa102 ksi

Elongation at Break

18%
17%

Reduction in Area

52%
53%

Compressive Strength

680 MPa98.6 ksi
700 MPa102 ksi

Shear Strength

475 MPa68.9 ksi
490 MPa71.1 ksi

Fatigue Strength (Endurance Limit)

340 MPa49.3 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
125 MPa·√m114 ksi·√in

Charpy V-Notch Impact (RT)

80 J59 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

240 HB
250 HB

Hardness, Rockwell C

22 HRC
24 HRC

Hardness, Vickers

252 HV
262 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 166 GPa24.1 Msi · Poisson's Ratio 0.3

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 36 W/m·K20.8 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 0°C32 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 6.6 % IACS · Electrical Resistivity 2.6×10⁻⁷ Ω·m10.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 13 / 100

Manufacturability

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

Machinability

44 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

48%
47%

Weldability

62 / 100
63 / 100

Formability (cold)

37 / 100
38 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.3 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 scaleP690QH

P690QH QT-100-150 vs P690QH QT-50-100 — frequently asked

What is the difference between P690QH QT-100-150 and P690QH QT-50-100?

P690QH QT-100-150 and P690QH QT-50-100 are two conditions of the same steel grade, P690QH: QT-100-150 (QT) versus QT-50-100 (QT). The chemistry is identical, so every difference below comes from the condition. Both yield at about 680 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (QT versus QT).

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

QT is the default P690QH 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.

When should I choose P690QH QT-100-150 over P690QH QT-50-100?

Pick P690QH QT-50-100 when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in P690QH QT-100-150 and P690QH 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.