Steel C15E2C Carburized+QT vs C15E2C +U
Steel · C15E2C temper comparison
C15E2C Carburized+QT and C15E2C +U are two conditions of the same steel grade, C15E2C: Carburized+QT (case hardened) versus +U (hot rolled). The chemistry is identical, so every difference below comes from the condition. C15E2C Carburized+QT is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 270 MPa (39.2 ksi) for C15E2C +U, about 78% more; tensile strength follows at 700 MPa (102 ksi) vs 440 MPa (63.8 ksi). In exchange, C15E2C +U is the more ductile: elongation 28% versus 12% for C15E2C Carburized+QT, and C15E2C Carburized+QT is harder (140 HB vs 120 HB). C15E2C +U runs hotter in service (350°C vs 180°C continuous). On the shop floor, C15E2C +U machines more easily (good vs poor) and C15E2C +U welds better (excellent vs poor).
C15E2C Carburized+QTChoose it when strength drives the design.
C15E2C +UChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.
C15E2C Carburized+QT vs C15E2C +U: 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
Shear Strength
Fatigue Strength (Endurance Limit)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
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 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,460°C2,660 °F · Liquidus Temperature 1,520°C2,768 °F
Thermal
How each material carries heat and how hot it can run.
Max Service Temperature (continuous)
Same in both: Thermal Conductivity 51 W/m·K29.5 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 247 J/g106 BTU/lb · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 10.8 % IACS · Electrical Resistivity 1.6×10⁻⁷ Ω·m6.3 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 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 40 / 100 · Brazeability / Solderability 80 / 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 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.
C15E2C Carburized+QT vs C15E2C +U — frequently asked
Is C15E2C Carburized+QT stronger than C15E2C +U?
Yes. C15E2C Carburized+QT has a typical yield strength of 480 MPa (69.6 ksi) against 270 MPa (39.2 ksi) for C15E2C +U — about 78% more. Tensile strength is 700 MPa (102 ksi) vs 440 MPa (63.8 ksi).
Which condition does FabDigit quote by default, Carburized+QT or +U?
+AC+C is the default C15E2C condition in the FabDigit quote flow (neither Carburized+QT nor +U). 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, C15E2C Carburized+QT or C15E2C +U?
C15E2C +U. Its machinability rates good (58/100) against poor (15/100) for C15E2C Carburized+QT; for welding the order is C15E2C +U first (excellent, 93/100) then C15E2C Carburized+QT (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in C15E2C Carburized+QT and C15E2C +U 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.