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Steel 8407 QT40-44 vs 8407 QT50-52

Steel · 8407 temper comparison

8407 QT40-44 and 8407 QT50-52 are two conditions of the same steel grade, 8407: QT40-44 (Q&T 40–44 HRC) versus QT50-52 (Q&T 50–52 HRC). The chemistry is identical, so every difference below comes from the condition. 8407 QT50-52 is the stronger of the two: yield strength 1,570 MPa (228 ksi) against 1,150 MPa (167 ksi) for 8407 QT40-44, about 37% more; tensile strength follows at 1,900 MPa (276 ksi) vs 1,350 MPa (196 ksi). In exchange, 8407 QT40-44 is the more ductile: elongation 12% versus 8% for 8407 QT50-52, and 8407 QT40-44 is harder (390 HB vs 180 HB). 8407 QT40-44 runs hotter in service (560°C vs 500°C continuous). On the shop floor, 8407 QT40-44 machines more easily (poor vs not recommended).

8407 QT40-44Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

8407 QT50-52Choose it when strength drives the design.

8407 QT40-44 vs 8407 QT50-52: properties

8407 QT40-448407 QT50-52

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,350 MPa196 ksi
1,900 MPa276 ksi

Yield Strength (0.2% offset)

1,150 MPa167 ksi
1,570 MPa228 ksi

Elongation at Break

12%
8%

Reduction in Area

45%
28%

Compressive Strength

1,400 MPa203 ksi
2,100 MPa305 ksi

Shear Strength

810 MPa117 ksi
1,140 MPa165 ksi

Fatigue Strength (Endurance Limit)

620 MPa89.9 ksi
800 MPa116 ksi

Fracture Toughness (K_IC)

45 MPa·√m41 ksi·√in
25 MPa·√m22.8 ksi·√in

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
10 J7.4 ft·lbf

Hardness, Brinell

390 HB
180 HB

Hardness, Rockwell C

42 HRC
51 HRC

Hardness, Vickers

412 HV
570 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 175 GPa25.4 Msi · Poisson's Ratio 0.3 · Hardness, Rockwell B 89 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.8 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

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

Max Service Temperature (continuous)

560°C1,040 °F
500°C932 °F

Same in both: Thermal Conductivity 25.5 W/m·K14.7 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.5 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 3.3 % IACS · Electrical Resistivity 5.2×10⁻⁷ Ω·m20.5 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V · Corrosion Resistance 18 / 100

Manufacturability

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

Machinability

28 / 100
10 / 100

Machinability Rating (AISI 1212 = 100 %)

22%
6%

Same in both: Weldability 45 / 100 · Formability (cold) 25 / 100 · Brazeability / Solderability 25 / 100 · Polishability 90 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 35 MJ/kg15,047 BTU/lb · Embodied Carbon (primary production) 2.8 kg CO₂/kg · Embodied Water 55 L/kg6.6 gal/lb · Typical Recycled Content 45%

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 scale8407

8407 QT40-44 vs 8407 QT50-52 — frequently asked

Is 8407 QT50-52 stronger than 8407 QT40-44?

Yes. 8407 QT50-52 has a typical yield strength of 1,570 MPa (228 ksi) against 1,150 MPa (167 ksi) for 8407 QT40-44 — about 37% more. Tensile strength is 1,900 MPa (276 ksi) vs 1,350 MPa (196 ksi).

Which condition does FabDigit quote by default, QT40-44 or QT50-52?

ANN is the default 8407 condition in the FabDigit quote flow (neither QT40-44 nor QT50-52). 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, 8407 QT40-44 or 8407 QT50-52?

8407 QT40-44. Its machinability rates poor (28/100) against not recommended (10/100) for 8407 QT50-52.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 8407 QT40-44 and 8407 QT50-52 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.