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Steel C55E +A vs C55E +N

Steel · C55E temper comparison

C55E +A and C55E +N are two conditions of the same steel grade, C55E: +A (annealed) versus +N (normalized). The chemistry is identical, so every difference below comes from the condition. C55E +N is the stronger of the two: yield strength 390 MPa (56.6 ksi) against 340 MPa (49.3 ksi) for C55E +A, about 15% more; tensile strength follows at 760 MPa (110 ksi) vs 620 MPa (89.9 ksi). In exchange, C55E +A is the more ductile: elongation 20% versus 14% for C55E +N, and C55E +N is harder (225 HB vs 190 HB).

C55E +AChoose it when the part is bent, formed or impact-loaded.

C55E +NChoose it when strength drives the design.

C55E +A vs C55E +N: properties

C55E +AC55E +N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

620 MPa89.9 ksi
760 MPa110 ksi

Yield Strength (0.2% offset)

340 MPa49.3 ksi
390 MPa56.6 ksi

Elongation at Break

20%
14%

Reduction in Area

45%
35%

Shear Strength

380 MPa55.1 ksi
460 MPa66.7 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
335 MPa48.6 ksi

Charpy V-Notch Impact (RT)

28 J20.7 ft·lbf
22 J16.2 ft·lbf

Hardness, Brinell

190 HB
225 HB

Hardness, Vickers

200 HV
235 HV

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 850 MPa123 ksi · Fracture Toughness (K_IC) 50 MPa·√m45.5 ksi·√in · Hardness, Rockwell C 24 HRC

Physical

Density and transition temperatures.

Same in both: Density 7.84 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,480°C2,696 °F

Thermal

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

Same in both: Thermal Conductivity 46 W/m·K26.6 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 9 % IACS · Electrical Resistivity 1.9×10⁻⁷ Ω·m7.48 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

55 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
60%

Weldability

30 / 100
25 / 100

Formability (cold)

45 / 100
28 / 100

Same in both: Brazeability / Solderability 55 / 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 40 L/kg4.8 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 scaleC55E

C55E +A vs C55E +N — frequently asked

Is C55E +N stronger than C55E +A?

Yes. C55E +N has a typical yield strength of 390 MPa (56.6 ksi) against 340 MPa (49.3 ksi) for C55E +A — about 15% more. Tensile strength is 760 MPa (110 ksi) vs 620 MPa (89.9 ksi).

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

+QT is the default C55E condition in the FabDigit quote flow (neither +A nor +N). 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, C55E +A or C55E +N?

C55E +A. Its machinability rates good (55/100) against fair (50/100) for C55E +N; for welding the order is C55E +A first (poor, 30/100) then C55E +N (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in C55E +A and C55E +N 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.