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Steel SUP6-N vs SUP6 QT44-48

Steel · SUP6 temper comparison

SUP6-N and SUP6 QT44-48 are two conditions of the same steel grade, SUP6: N (normalized) versus QT44-48 (Q&T 44–48 HRC). The chemistry is identical, so every difference below comes from the condition. SUP6 QT44-48 is the stronger of the two: yield strength 1,450 MPa (210 ksi) against 640 MPa (92.8 ksi) for SUP6-N, about 127% more; tensile strength follows at 1,620 MPa (235 ksi) vs 1,050 MPa (152 ksi). In exchange, SUP6-N is the more ductile: elongation 13% versus 11% for SUP6 QT44-48, and SUP6 QT44-48 is harder (444 HB vs 300 HB). SUP6-N runs hotter in service (300°C vs 230°C continuous). On the shop floor, SUP6-N machines more easily (fair vs poor).

SUP6-NChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SUP6 QT44-48Choose it when strength drives the design.

SUP6-N vs SUP6 QT44-48: properties

SUP6-NSUP6 QT44-48

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,050 MPa152 ksi
1,620 MPa235 ksi

Yield Strength (0.2% offset)

640 MPa92.8 ksi
1,450 MPa210 ksi

Elongation at Break

13%
11%

Compressive Strength

680 MPa98.6 ksi
1,500 MPa218 ksi

Shear Strength

640 MPa92.8 ksi
980 MPa142 ksi

Fatigue Strength (Endurance Limit)

470 MPa68.2 ksi
700 MPa102 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
42 MPa·√m38.2 ksi·√in

Charpy V-Notch Impact (RT)

18 J13.3 ft·lbf
14 J10.3 ft·lbf

Hardness, Brinell

300 HB
444 HB

Hardness, Rockwell C

31 HRC
46 HRC

Hardness, Vickers

315 HV
465 HV

Same in both: Elastic (Young's) Modulus 206 GPa29.9 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 32%

Physical

Density and transition temperatures.

Same in both: Density 7.75 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.

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

300°C572 °F
230°C446 °F

Same in both: Specific Heat Capacity 475 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7 % IACS
6.6 % IACS

Electrical Resistivity

2.46×10⁻⁷ Ω·m9.69 µΩ·in
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) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

40 / 100
22 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
25%

Weldability

20 / 100
15 / 100

Formability (cold)

15 / 100
8 / 100

Same in both: Castability 35 / 100 · Brazeability / Solderability 25 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 45 L/kg5.4 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 scaleSUP6

SUP6-N vs SUP6 QT44-48 — frequently asked

Is SUP6 QT44-48 stronger than SUP6-N?

Yes. SUP6 QT44-48 has a typical yield strength of 1,450 MPa (210 ksi) against 640 MPa (92.8 ksi) for SUP6-N — about 127% more. Tensile strength is 1,620 MPa (235 ksi) vs 1,050 MPa (152 ksi).

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

QT44-48 is the default SUP6 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.

Which is easier to machine, SUP6-N or SUP6 QT44-48?

SUP6-N. Its machinability rates fair (40/100) against poor (22/100) for SUP6 QT44-48; for welding the order is SUP6-N first (poor, 20/100) then SUP6 QT44-48 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SUP6-N and SUP6 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.