Steel 6CrW2Si-CD vs 6CrW2Si QT-56-58HRC
Steel · 6CrW2Si temper comparison
6CrW2Si-CD and 6CrW2Si QT-56-58HRC are two conditions of the same steel grade, 6CrW2Si: CD (cold drawn) versus QT-56-58HRC. The chemistry is identical, so every difference below comes from the condition. 6CrW2Si QT-56-58HRC is the stronger of the two: yield strength 1,750 MPa (254 ksi) against 640 MPa (92.8 ksi) for 6CrW2Si-CD, about 173% more; tensile strength follows at 2,100 MPa (305 ksi) vs 880 MPa (128 ksi). In exchange, 6CrW2Si-CD is the more ductile: elongation 10% versus 2% for 6CrW2Si QT-56-58HRC, and 6CrW2Si-CD is harder (270 HB vs 240 HB). 6CrW2Si-CD runs hotter in service (200°C vs 180°C continuous). On the shop floor, 6CrW2Si-CD machines more easily (fair vs not recommended).
6CrW2Si-CDChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
6CrW2Si QT-56-58HRCChoose it when strength drives the design.
6CrW2Si-CD vs 6CrW2Si QT-56-58HRC: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Vickers
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.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 33 W/m·K19.1 BTU/hr·ft·°F · 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.
Same in both: Electrical Resistivity 2.8×10⁻⁷ Ω·m11 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
Machinability Rating (AISI 1212 = 100 %)
Formability (cold)
Same in both: Weldability 20 / 100 · 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.
6CrW2Si-CD vs 6CrW2Si QT-56-58HRC — frequently asked
Is 6CrW2Si QT-56-58HRC stronger than 6CrW2Si-CD?
Yes. 6CrW2Si QT-56-58HRC has a typical yield strength of 1,750 MPa (254 ksi) against 640 MPa (92.8 ksi) for 6CrW2Si-CD — about 173% more. Tensile strength is 2,100 MPa (305 ksi) vs 880 MPa (128 ksi).
Which condition does FabDigit quote by default, CD or QT-56-58HRC?
Annealed is the default 6CrW2Si condition in the FabDigit quote flow (neither CD nor QT-56-58HRC). 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-56-58HRC?
6CrW2Si-CD. Its machinability rates fair (38/100) against not recommended (5/100) for 6CrW2Si QT-56-58HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 6CrW2Si-CD and 6CrW2Si QT-56-58HRC 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.