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Steel T15 QT-60-62 vs T15 QT-65-67

Steel · T15 temper comparison

T15 QT-60-62 and T15 QT-65-67 are two conditions of the same steel grade, T15: QT-60-62 (hardened & triple tempered to 60–62 HRC) versus QT-65-67 (hardened & triple tempered to 65–67 HRC). The chemistry is identical, so every difference below comes from the condition. Both yield at about 500 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (hardened & triple tempered to 60–62 HRC versus hardened & triple tempered to 65–67 HRC). T15 QT-60-62 is the more ductile: elongation 1% versus 0.3% for T15 QT-65-67, and T15 QT-65-67 is harder (66 HRC vs 61 HRC). On the shop floor, T15 QT-65-67 welds better (poor vs not recommended).

T15 QT-60-62Choose it when the part is bent, formed or impact-loaded.

T15 QT-65-67Choose it when it will be welded.

T15 QT-60-62 vs T15 QT-65-67: properties

T15 QT-60-62T15 QT-65-67

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

222 GPa32.2 Msi
225 GPa32.6 Msi

Tensile Strength (Ultimate)

2,100 MPa305 ksi
2,200 MPa319 ksi

Elongation at Break

1%
0.3%

Compressive Strength

3,100 MPa450 ksi
3,650 MPa529 ksi

Charpy V-Notch Impact (RT)

6 J4.4 ft·lbf
3 J2.2 ft·lbf

Hardness, Rockwell C

61 HRC
66 HRC

Hardness, Vickers

745 HV
870 HV

Same in both: Shear Modulus 84 GPa12.2 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Yield Strength (0.2% offset) 500 MPa72.5 ksi · Reduction in Area 22% · Hardness, Brinell 255 HB

Physical

Density and transition temperatures.

Same in both: Density 8.19 g/cm³0.3 lb/in³ · Melting Point (Solidus) 1,230°C2,246 °F · Liquidus Temperature 1,420°C2,588 °F

Thermal

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

Thermal Conductivity

23 W/m·K13.3 BTU/hr·ft·°F
21 W/m·K12.1 BTU/hr·ft·°F

Max Service Temperature (continuous)

590°C1,094 °F
620°C1,148 °F

Same in both: Specific Heat Capacity 420 J/kg·K0.1 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.2 µm/m·K6.2 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.7 % IACS · Electrical Resistivity 6.5×10⁻⁷ Ω·m25.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V · Corrosion Resistance 15 / 100

Manufacturability

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

Machinability

6 / 100
4 / 100

Machinability Rating (AISI 1212 = 100 %)

5%
3%

Weldability

10 / 100
20 / 100

Formability (cold)

2 / 100
1 / 100

Same in both: Brazeability / Solderability 45 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 52 MJ/kg22,356 BTU/lb · Embodied Carbon (primary production) 3.8 kg CO₂/kg · Embodied Water 80 L/kg9.6 gal/lb · Typical Recycled Content 30%

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 scaleT15

T15 QT-60-62 vs T15 QT-65-67 — frequently asked

What is the difference between T15 QT-60-62 and T15 QT-65-67?

T15 QT-60-62 and T15 QT-65-67 are two conditions of the same steel grade, T15: QT-60-62 (hardened & triple tempered to 60–62 HRC) versus QT-65-67 (hardened & triple tempered to 65–67 HRC). The chemistry is identical, so every difference below comes from the condition. Both yield at about 500 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (hardened & triple tempered to 60–62 HRC versus hardened & triple tempered to 65–67 HRC).

Which condition does FabDigit quote by default, QT-60-62 or QT-65-67?

ANN is the default T15 condition in the FabDigit quote flow (neither QT-60-62 nor QT-65-67). 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, T15 QT-60-62 or T15 QT-65-67?

T15 QT-65-67. Its weldability rates poor (20/100) against not recommended (10/100) for T15 QT-60-62.

Ready to make it?

Upload a CAD file and FabDigit prices the part in T15 QT-60-62 and T15 QT-65-67 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.