Steel SNCM630-CD vs SNCM630 QT-42-46HRC
Steel · SNCM630 temper comparison
SNCM630-CD and SNCM630 QT-42-46HRC are two conditions of the same steel grade, SNCM630: CD (cold drawn) versus QT-42-46HRC. The chemistry is identical, so every difference below comes from the condition. SNCM630 QT-42-46HRC is the stronger of the two: yield strength 1,330 MPa (193 ksi) against 800 MPa (116 ksi) for SNCM630-CD, about 66% more; tensile strength follows at 1,450 MPa (210 ksi) vs 950 MPa (138 ksi). SNCM630 QT-42-46HRC is harder — 325 HB against 280 HB for SNCM630-CD — which matters for wear surfaces and threads. SNCM630-CD runs hotter in service (350°C vs 250°C continuous) and SNCM630-CD conducts heat better (38 W/m·K vs 34 W/m·K). On the shop floor, SNCM630-CD machines more easily (fair vs poor).
SNCM630-CDChoose it when the part sees heat, or when the part is machined in volume.
SNCM630 QT-42-46HRCChoose it when strength drives the design, or when surface hardness matters.
SNCM630-CD vs SNCM630 QT-42-46HRC: 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)
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 · Charpy V-Notch Impact (RT) 25 J18.4 ft·lbf
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
Max Service Temperature (continuous)
Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V
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 30 / 100 · Castability 45 / 100 · Brazeability / Solderability 50 / 100 · Polishability 72 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.5 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.
SNCM630-CD vs SNCM630 QT-42-46HRC — frequently asked
Is SNCM630 QT-42-46HRC stronger than SNCM630-CD?
Yes. SNCM630 QT-42-46HRC has a typical yield strength of 1,330 MPa (193 ksi) against 800 MPa (116 ksi) for SNCM630-CD — about 66% more. Tensile strength is 1,450 MPa (210 ksi) vs 950 MPa (138 ksi).
Which condition does FabDigit quote by default, CD or QT-42-46HRC?
QT-H is the default SNCM630 condition in the FabDigit quote flow (neither CD nor QT-42-46HRC). 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, SNCM630-CD or SNCM630 QT-42-46HRC?
SNCM630-CD. Its machinability rates fair (48/100) against poor (24/100) for SNCM630 QT-42-46HRC.
Ready to make it?
Upload a CAD file and FabDigit prices the part in SNCM630-CD and SNCM630 QT-42-46HRC 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.