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Steel C2C +U vs C2C +U+C

Steel · C2C temper comparison

C2C +U and C2C +U+C are two conditions of the same steel grade, C2C: +U (hot rolled) versus +U+C (hot rolled then cold drawn). The chemistry is identical, so every difference below comes from the condition. C2C +U+C is the stronger of the two: yield strength 340 MPa (49.3 ksi) against 210 MPa (30.5 ksi) for C2C +U, about 62% more; tensile strength follows at 400 MPa (58 ksi) vs 320 MPa (46.4 ksi). In exchange, C2C +U is the more ductile: elongation 40% versus 12% for C2C +U+C, and C2C +U+C is harder (120 HB vs 95 HB).

C2C +UChoose it when the part is bent, formed or impact-loaded.

C2C +U+CChoose it when strength drives the design.

C2C +U vs C2C +U+C: properties

C2C +UC2C +U+C

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

320 MPa46.4 ksi
400 MPa58 ksi

Yield Strength (0.2% offset)

210 MPa30.5 ksi
340 MPa49.3 ksi

Elongation at Break

40%
12%

Reduction in Area

72%
62%

Compressive Strength

210 MPa30.5 ksi
340 MPa49.3 ksi

Shear Strength

205 MPa29.7 ksi
255 MPa37 ksi

Fatigue Strength (Endurance Limit)

155 MPa22.5 ksi
195 MPa28.3 ksi

Charpy V-Notch Impact (RT)

110 J81.1 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

95 HB
120 HB

Hardness, Rockwell B

55 HRB
68 HRB

Hardness, Vickers

100 HV
126 HV

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 · Fracture Toughness (K_IC) 130 MPa·√m118 ksi·√in

Physical

Density and transition temperatures.

Same in both: Density 7.87 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,500°C2,732 °F · Liquidus Temperature 1,535°C2,795 °F

Thermal

How each material carries heat and how hot it can run.

Same in both: Thermal Conductivity 60 W/m·K34.7 BTU/hr·ft·°F · Specific Heat Capacity 480 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 247 J/g106 BTU/lb · Max Service Temperature (continuous) 300°C572 °F · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 12 % IACS · Electrical Resistivity 1.45×10⁻⁷ Ω·m5.71 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

42 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

48%
52%

Formability (cold)

98 / 100
92 / 100

Same in both: Weldability 96 / 100 · Brazeability / Solderability 75 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 26 MJ/kg11,178 BTU/lb · Embodied Carbon (primary production) 2.1 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleC2C

C2C +U vs C2C +U+C — frequently asked

Is C2C +U+C stronger than C2C +U?

Yes. C2C +U+C has a typical yield strength of 340 MPa (49.3 ksi) against 210 MPa (30.5 ksi) for C2C +U — about 62% more. Tensile strength is 400 MPa (58 ksi) vs 320 MPa (46.4 ksi).

Which condition does FabDigit quote by default, +U or +U+C?

+U+C is the default C2C condition in the FabDigit quote flow. 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, C2C +U or C2C +U+C?

C2C +U+C, by a small margin. Both rate fair for machinability — 48/100 against 42/100 for C2C +U.

Ready to make it?

Upload a CAD file and FabDigit prices the part in C2C +U and C2C +U+C 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.