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Steel 6CrW2Si-CD vs 6CrW2Si QT-40-43HRC

Steel · 6CrW2Si temper comparison

6CrW2Si-CD and 6CrW2Si QT-40-43HRC are two conditions of the same steel grade, 6CrW2Si: CD (cold drawn) versus QT-40-43HRC. The chemistry is identical, so every difference below comes from the condition. 6CrW2Si QT-40-43HRC is the stronger of the two: yield strength 1,180 MPa (171 ksi) against 640 MPa (92.8 ksi) for 6CrW2Si-CD, about 84% more; tensile strength follows at 1,330 MPa (193 ksi) vs 880 MPa (128 ksi). 6CrW2Si QT-40-43HRC is the more ductile: elongation 12% versus 10% for 6CrW2Si-CD, and 6CrW2Si QT-40-43HRC is harder (390 HB vs 270 HB). 6CrW2Si QT-40-43HRC runs hotter in service (430°C vs 200°C continuous). On the shop floor, 6CrW2Si-CD machines more easily (fair vs poor) and 6CrW2Si-CD welds better (poor vs not recommended).

6CrW2Si-CDChoose it when the part is machined in volume, or when it will be welded.

6CrW2Si QT-40-43HRCChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

6CrW2Si-CD vs 6CrW2Si QT-40-43HRC: properties

6CrW2Si-CD6CrW2Si QT-40-43HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

880 MPa128 ksi
1,330 MPa193 ksi

Yield Strength (0.2% offset)

640 MPa92.8 ksi
1,180 MPa171 ksi

Elongation at Break

10%
12%

Reduction in Area

35%
40%

Compressive Strength

1,150 MPa167 ksi
1,700 MPa247 ksi

Shear Strength

560 MPa81.2 ksi
800 MPa116 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
560 MPa81.2 ksi

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

270 HB
390 HB

Hardness, Vickers

285 HV
415 HV

Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 165 GPa23.9 Msi · Poisson's Ratio 0.29 · Hardness, Rockwell B 99 HRB

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.

Thermal Conductivity

33 W/m·K19.1 BTU/hr·ft·°F
32 W/m·K18.5 BTU/hr·ft·°F

Max Service Temperature (continuous)

200°C392 °F
430°C806 °F

Same in both: Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.4 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 Resistivity

2.8×10⁻⁷ Ω·m11 µΩ·in
2.85×10⁻⁷ Ω·m11.2 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

38 / 100
18 / 100

Machinability Rating (AISI 1212 = 100 %)

32%
15%

Weldability

20 / 100
10 / 100

Formability (cold)

15 / 100
5 / 100

Same in both: Castability 20 / 100 · Brazeability / Solderability 45 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 35 MJ/kg15,047 BTU/lb · Embodied Carbon (primary production) 2.6 kg CO₂/kg · Embodied Water 60 L/kg7.2 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 scale6CrW2Si

6CrW2Si-CD vs 6CrW2Si QT-40-43HRC — frequently asked

Is 6CrW2Si QT-40-43HRC stronger than 6CrW2Si-CD?

Yes. 6CrW2Si QT-40-43HRC has a typical yield strength of 1,180 MPa (171 ksi) against 640 MPa (92.8 ksi) for 6CrW2Si-CD — about 84% more. Tensile strength is 1,330 MPa (193 ksi) vs 880 MPa (128 ksi).

Which condition does FabDigit quote by default, CD or QT-40-43HRC?

Annealed is the default 6CrW2Si condition in the FabDigit quote flow (neither CD nor QT-40-43HRC). 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, 6CrW2Si-CD or 6CrW2Si QT-40-43HRC?

6CrW2Si-CD. Its machinability rates fair (38/100) against poor (18/100) for 6CrW2Si QT-40-43HRC; for welding the order is 6CrW2Si-CD first (poor, 20/100) then 6CrW2Si QT-40-43HRC (not recommended, 10/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 6CrW2Si-CD and 6CrW2Si QT-40-43HRC 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.