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Steel 55SiMnVB-CD vs 55SiMnVB-QT460

Steel · 55SiMnVB temper comparison

55SiMnVB-CD and 55SiMnVB-QT460 are two conditions of the same steel grade, 55SiMnVB: CD (cold drawn) versus QT460 (oil quenched 860 °C, tempered 460 °C). The chemistry is identical, so every difference below comes from the condition. 55SiMnVB-QT460 is the stronger of the two: yield strength 1,320 MPa (191 ksi) against 780 MPa (113 ksi) for 55SiMnVB-CD, about 69% more; tensile strength follows at 1,500 MPa (218 ksi) vs 950 MPa (138 ksi). In exchange, 55SiMnVB-CD is the more ductile: elongation 9% versus 8% for 55SiMnVB-QT460, and 55SiMnVB-QT460 is harder (425 HB vs 285 HB). 55SiMnVB-CD runs hotter in service (300°C vs 250°C continuous). On the shop floor, 55SiMnVB-CD machines more easily (fair vs poor).

55SiMnVB-CDChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

55SiMnVB-QT460Choose it when strength drives the design.

55SiMnVB-CD vs 55SiMnVB-QT460: properties

55SiMnVB-CD55SiMnVB-QT460

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

950 MPa138 ksi
1,500 MPa218 ksi

Yield Strength (0.2% offset)

780 MPa113 ksi
1,320 MPa191 ksi

Elongation at Break

9%
8%

Reduction in Area

30%
32%

Compressive Strength

800 MPa116 ksi
1,350 MPa196 ksi

Shear Strength

580 MPa84.1 ksi
900 MPa131 ksi

Fatigue Strength (Endurance Limit)

420 MPa60.9 ksi
680 MPa98.6 ksi

Fracture Toughness (K_IC)

60 MPa·√m54.6 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

14 J10.3 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

285 HB
425 HB

Hardness, Rockwell C

30 HRC
45 HRC

Hardness, Vickers

300 HV
450 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

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.

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Max Service Temperature (continuous)

300°C572 °F
250°C482 °F

Same in both: Specific Heat Capacity 470 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.

Electrical Conductivity

7 % IACS
6.4 % IACS

Electrical Resistivity

2.5×10⁻⁷ Ω·m9.84 µΩ·in
2.7×10⁻⁷ Ω·m10.6 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 11 / 100

Manufacturability

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

Machinability

45 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

38%
20%

Weldability

25 / 100
20 / 100

Formability (cold)

25 / 100
10 / 100

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

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 27 MJ/kg11,608 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 60 L/kg7.2 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 scale55SiMnVB

55SiMnVB-CD vs 55SiMnVB-QT460 — frequently asked

Is 55SiMnVB-QT460 stronger than 55SiMnVB-CD?

Yes. 55SiMnVB-QT460 has a typical yield strength of 1,320 MPa (191 ksi) against 780 MPa (113 ksi) for 55SiMnVB-CD — about 69% more. Tensile strength is 1,500 MPa (218 ksi) vs 950 MPa (138 ksi).

Which condition does FabDigit quote by default, CD or QT460?

QT460 is the default 55SiMnVB 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, 55SiMnVB-CD or 55SiMnVB-QT460?

55SiMnVB-CD. Its machinability rates fair (45/100) against poor (25/100) for 55SiMnVB-QT460; for welding the order is 55SiMnVB-CD first (poor, 25/100) then 55SiMnVB-QT460 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 55SiMnVB-CD and 55SiMnVB-QT460 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.