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Steel C35E +A vs C35E +QT

Steel · C35E temper comparison

C35E +A and C35E +QT are two conditions of the same steel grade, C35E: +A (annealed) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. C35E +QT is the stronger of the two: yield strength 430 MPa (62.4 ksi) against 300 MPa (43.5 ksi) for C35E +A, about 43% more; tensile strength follows at 660 MPa (95.7 ksi) vs 540 MPa (78.3 ksi). In exchange, C35E +A is the more ductile: elongation 24% versus 20% for C35E +QT, and C35E +QT is harder (200 HB vs 160 HB). On the shop floor, C35E +A welds better (good vs fair).

C35E +AChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

C35E +QTChoose it when strength drives the design.

C35E +A vs C35E +QT: properties

C35E +AC35E +QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

540 MPa78.3 ksi
660 MPa95.7 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
430 MPa62.4 ksi

Elongation at Break

24%
20%

Reduction in Area

55%
50%

Shear Strength

340 MPa49.3 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
300 MPa43.5 ksi

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
50 J36.9 ft·lbf

Hardness, Brinell

160 HB
200 HB

Hardness, Rockwell B

84 HRB
93 HRB

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 440 MPa63.8 ksi · Fracture Toughness (K_IC) 60 MPa·√m54.6 ksi·√in · Hardness, Rockwell C 15 HRC · Hardness, Vickers 210 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 1,495°C2,723 °F

Thermal

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

Same in both: Thermal Conductivity 47 W/m·K27.2 BTU/hr·ft·°F · 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 · 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) -0.6 V · Corrosion Resistance 10 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

60 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
65%

Weldability

60 / 100
50 / 100

Formability (cold)

60 / 100
40 / 100

Same in both: 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) 2 kg CO₂/kg · Embodied Water 45 L/kg5.4 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleC35E

C35E +A vs C35E +QT — frequently asked

Is C35E +QT stronger than C35E +A?

Yes. C35E +QT has a typical yield strength of 430 MPa (62.4 ksi) against 300 MPa (43.5 ksi) for C35E +A — about 43% more. Tensile strength is 660 MPa (95.7 ksi) vs 540 MPa (78.3 ksi).

Which condition does FabDigit quote by default, +A or +QT?

+QT is the default C35E 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, C35E +A or C35E +QT?

C35E +A, by a small margin. Both rate good for machinability — 60/100 against 55/100 for C35E +QT; for welding the order is C35E +A first (good, 60/100) then C35E +QT (fair, 50/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C35E +A and C35E +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.