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Steel Q960Q-QT vs Q960Q QT+SR

Steel · Q960Q temper comparison

Q960Q-QT and Q960Q QT+SR are two conditions of the same steel grade, Q960Q: QT (quenched and tempered) versus QT+SR. The chemistry is identical, so every difference below comes from the condition. Q960Q-QT is the stronger of the two: yield strength 1,010 MPa (146 ksi) against 950 MPa (138 ksi) for Q960Q QT+SR, about 6% more. Q960Q-QT is harder — 340 HB against 320 HB for Q960Q QT+SR — which matters for wear surfaces and threads.

Q960Q-QTChoose it when strength drives the design, or when surface hardness matters.

Q960Q-QT vs Q960Q QT+SR: properties

Q960Q-QTQ960Q QT+SR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,050 MPa152 ksi
1,010 MPa146 ksi

Yield Strength (0.2% offset)

1,010 MPa146 ksi
950 MPa138 ksi

Elongation at Break

13%
14%

Reduction in Area

50%
53%

Compressive Strength

1,010 MPa146 ksi
950 MPa138 ksi

Shear Strength

660 MPa95.7 ksi
635 MPa92.1 ksi

Fatigue Strength (Endurance Limit)

470 MPa68.2 ksi
460 MPa66.7 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
80 J59 ft·lbf

Hardness, Brinell

340 HB
320 HB

Hardness, Rockwell C

36 HRC
34 HRC

Hardness, Vickers

355 HV
335 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

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,490°C2,714 °F

Thermal

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

Same in both: Thermal Conductivity 34 W/m·K19.6 BTU/hr·ft·°F · Specific Heat Capacity 470 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) 250°C482 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7 % IACS · Electrical Resistivity 2.5×10⁻⁷ Ω·m9.84 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

30 / 100
33 / 100

Machinability Rating (AISI 1212 = 100 %)

32%
35%

Weldability

50 / 100
53 / 100

Formability (cold)

32 / 100
34 / 100

Same in both: Brazeability / Solderability 35 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.4 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 scaleQ960Q

Q960Q-QT vs Q960Q QT+SR — frequently asked

Is Q960Q-QT stronger than Q960Q QT+SR?

Yes. Q960Q-QT has a typical yield strength of 1,010 MPa (146 ksi) against 950 MPa (138 ksi) for Q960Q QT+SR — about 6% more. Tensile strength is 1,050 MPa (152 ksi) vs 1,010 MPa (146 ksi).

Which condition does FabDigit quote by default, QT or QT+SR?

QT is the default Q960Q 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 Q960Q-QT over Q960Q QT+SR?

Pick Q960Q-QT when strength drives the design, or when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Q960Q-QT and Q960Q QT+SR 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.