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Steel 1.2714 QT38-42 vs 1.2714 QT44-48

Steel · 1.2714 temper comparison

1.2714 QT38-42 and 1.2714 QT44-48 are two conditions of the same steel grade, 1.2714: QT38-42 (Q&T 38–42 HRC) versus QT44-48 (Q&T 44–48 HRC). The chemistry is identical, so every difference below comes from the condition. 1.2714 QT44-48 is the stronger of the two: yield strength 1,350 MPa (196 ksi) against 1,120 MPa (162 ksi) for 1.2714 QT38-42, about 21% more; tensile strength follows at 1,550 MPa (225 ksi) vs 1,300 MPa (189 ksi). In exchange, 1.2714 QT38-42 is the more ductile: elongation 11% versus 9% for 1.2714 QT44-48, and 1.2714 QT38-42 is harder (375 HB vs 295 HB). 1.2714 QT38-42 runs hotter in service (450°C vs 350°C continuous). On the shop floor, 1.2714 QT38-42 machines more easily (fair vs poor).

1.2714 QT38-42Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

1.2714 QT44-48Choose it when strength drives the design.

1.2714 QT38-42 vs 1.2714 QT44-48: properties

1.2714 QT38-421.2714 QT44-48

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,300 MPa189 ksi
1,550 MPa225 ksi

Yield Strength (0.2% offset)

1,120 MPa162 ksi
1,350 MPa196 ksi

Elongation at Break

11%
9%

Reduction in Area

38%
30%

Fatigue Strength (Endurance Limit)

580 MPa84.1 ksi
650 MPa94.3 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
50 MPa·√m45.5 ksi·√in

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
16 J11.8 ft·lbf

Hardness, Brinell

375 HB
295 HB

Hardness, Rockwell C

40 HRC
46 HRC

Hardness, Vickers

400 HV
460 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 900 MPa131 ksi · Shear Strength 620 MPa89.9 ksi

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 1,480°C2,696 °F

Thermal

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

Max Service Temperature (continuous)

450°C842 °F
350°C662 °F

Same in both: Thermal Conductivity 34 W/m·K19.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.5 µm/m·K6.9 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

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

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

35 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

32%
20%

Same in both: Weldability 25 / 100 · Formability (cold) 12 / 100 · Brazeability / Solderability 30 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 50 L/kg6 gal/lb · Typical Recycled Content 35%

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 scale1.2714

1.2714 QT38-42 vs 1.2714 QT44-48 — frequently asked

Is 1.2714 QT44-48 stronger than 1.2714 QT38-42?

Yes. 1.2714 QT44-48 has a typical yield strength of 1,350 MPa (196 ksi) against 1,120 MPa (162 ksi) for 1.2714 QT38-42 — about 21% more. Tensile strength is 1,550 MPa (225 ksi) vs 1,300 MPa (189 ksi).

Which condition does FabDigit quote by default, QT38-42 or QT44-48?

Prehard is the default 1.2714 condition in the FabDigit quote flow (neither QT38-42 nor QT44-48). 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 is easier to machine, 1.2714 QT38-42 or 1.2714 QT44-48?

1.2714 QT38-42. Its machinability rates fair (35/100) against poor (22/100) for 1.2714 QT44-48.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 1.2714 QT38-42 and 1.2714 QT44-48 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.