Steel 35CrMnSiA-CD vs 35CrMnSiA-QT300
Steel · 35CrMnSiA temper comparison
35CrMnSiA-CD and 35CrMnSiA-QT300 are two conditions of the same steel grade, 35CrMnSiA: CD (cold drawn) versus QT300 (Q&T). The chemistry is identical, so every difference below comes from the condition. 35CrMnSiA-QT300 is the stronger of the two: yield strength 1,330 MPa (193 ksi) against 720 MPa (104 ksi) for 35CrMnSiA-CD, about 85% more; tensile strength follows at 1,550 MPa (225 ksi) vs 880 MPa (128 ksi). 35CrMnSiA-QT300 is the more ductile: elongation 11% versus 9% for 35CrMnSiA-CD, and 35CrMnSiA-QT300 is harder (430 HB vs 265 HB). 35CrMnSiA-CD runs hotter in service (350°C vs 250°C continuous) and 35CrMnSiA-CD conducts heat better (42 W/m·K vs 36 W/m·K). On the shop floor, 35CrMnSiA-CD machines more easily (fair vs poor).
35CrMnSiA-CDChoose it when the part sees heat, or when the part is machined in volume.
35CrMnSiA-QT300Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
35CrMnSiA-CD vs 35CrMnSiA-QT300: 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)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29
Physical
Density and transition temperatures.
Same in both: Density 7.82 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
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 470 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 · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 12 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 35 / 100 · Polishability 75 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 29 MJ/kg12,468 BTU/lb · Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 45 L/kg5.4 gal/lb · Typical Recycled Content 25%
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.
35CrMnSiA-CD vs 35CrMnSiA-QT300 — frequently asked
Is 35CrMnSiA-QT300 stronger than 35CrMnSiA-CD?
Yes. 35CrMnSiA-QT300 has a typical yield strength of 1,330 MPa (193 ksi) against 720 MPa (104 ksi) for 35CrMnSiA-CD — about 85% more. Tensile strength is 1,550 MPa (225 ksi) vs 880 MPa (128 ksi).
Which condition does FabDigit quote by default, CD or QT300?
QT230 is the default 35CrMnSiA condition in the FabDigit quote flow (neither CD nor QT300). 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, 35CrMnSiA-CD or 35CrMnSiA-QT300?
35CrMnSiA-CD. Its machinability rates fair (50/100) against poor (32/100) for 35CrMnSiA-QT300; for welding the order is 35CrMnSiA-CD first (poor, 28/100) then 35CrMnSiA-QT300 (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 35CrMnSiA-CD and 35CrMnSiA-QT300 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.