Steel 35#-CD vs 35#-QT
Steel · 35# temper comparison
35#-CD and 35#-QT are two conditions of the same steel grade, 35#: CD (cold drawn) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 35#-CD is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 470 MPa (68.2 ksi) for 35#-QT, about 11% more. In exchange, 35#-QT is the more ductile: elongation 19% versus 13% for 35#-CD, and 35#-QT is harder (210 HB vs 190 HB). On the shop floor, 35#-CD machines more easily (65 vs 55 out of 100) and 35#-CD welds better (good vs fair).
35#-CDChoose it when strength drives the design, or when the part is machined in volume.
35#-QTChoose it when the part is bent, formed or impact-loaded.
35#-CD vs 35#-QT: 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
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Shear Strength 400 MPa58 ksi · Hardness, Vickers 168 HV
Physical
Density and transition temperatures.
Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F · Liquidus Temperature 1,500°C2,732 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 49 W/m·K28.3 BTU/hr·ft·°F · Specific Heat Capacity 477 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.6 µm/m·K6.4 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.65 V · Corrosion Resistance 11 / 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: Castability 35 / 100 · Brazeability / Solderability 65 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg · Embodied Water 40 L/kg4.8 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.
35#-CD vs 35#-QT — frequently asked
Is 35#-CD stronger than 35#-QT?
Yes. 35#-CD has a typical yield strength of 520 MPa (75.4 ksi) against 470 MPa (68.2 ksi) for 35#-QT — about 11% more. Tensile strength is 640 MPa (92.8 ksi) vs 700 MPa (102 ksi).
Which condition does FabDigit quote by default, CD or QT?
HR is the default 35# condition in the FabDigit quote flow (neither CD nor QT). 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, 35#-CD or 35#-QT?
35#-CD, by a small margin. Both rate good for machinability — 65/100 against 55/100 for 35#-QT; for welding the order is 35#-CD first (good, 55/100) then 35#-QT (fair, 45/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 35#-CD and 35#-QT 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.