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Steel Q550-N vs Q550 Q-F

Steel · Q550 temper comparison

Q550-N and Q550 Q-F are two conditions of the same steel grade, Q550: N (normalized) versus Q-F (Q550QF). The chemistry is identical, so every difference below comes from the condition. Q550 Q-F is the stronger of the two: yield strength 610 MPa (88.5 ksi) against 575 MPa (83.4 ksi) for Q550-N, about 6% more. Q550 Q-F is harder — 19 HRC against 18 HRC for Q550-N — which matters for wear surfaces and threads.

Q550 Q-FChoose it when strength drives the design, or when surface hardness matters.

Q550-N vs Q550 Q-F: properties

Q550-NQ550 Q-F

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

700 MPa102 ksi
705 MPa102 ksi

Yield Strength (0.2% offset)

575 MPa83.4 ksi
610 MPa88.5 ksi

Elongation at Break

17%
18%

Reduction in Area

55%
60%

Compressive Strength

575 MPa83.4 ksi
610 MPa88.5 ksi

Shear Strength

420 MPa60.9 ksi
425 MPa61.6 ksi

Fatigue Strength (Endurance Limit)

315 MPa45.7 ksi
320 MPa46.4 ksi

Fracture Toughness (K_IC)

95 MPa·√m86.5 ksi·√in
140 MPa·√m127 ksi·√in

Charpy V-Notch Impact (RT)

100 J73.8 ft·lbf
170 J125 ft·lbf

Hardness, Rockwell C

18 HRC
19 HRC

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Hardness, Brinell 215 HB · Hardness, Rockwell B 96 HRB · Hardness, Vickers 225 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 1,500°C2,732 °F

Thermal

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

Thermal Conductivity

44 W/m·K25.4 BTU/hr·ft·°F
40 W/m·K23.1 BTU/hr·ft·°F

Min Service Temperature

-20°C-4 °F
-60°C-76 °F

Same in both: Specific Heat Capacity 470 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 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7.2 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.4×10⁻⁷ Ω·m9.45 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

48 / 100
47 / 100

Machinability Rating (AISI 1212 = 100 %)

53%
52%

Weldability

62 / 100
68 / 100

Formability (cold)

55 / 100
48 / 100

Same in both: Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2.1 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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleQ550

Q550-N vs Q550 Q-F — frequently asked

Is Q550 Q-F stronger than Q550-N?

Yes. Q550 Q-F has a typical yield strength of 610 MPa (88.5 ksi) against 575 MPa (83.4 ksi) for Q550-N — about 6% more. Tensile strength is 705 MPa (102 ksi) vs 700 MPa (102 ksi).

Which condition does FabDigit quote by default, N or Q-F?

M-D is the default Q550 condition in the FabDigit quote flow (neither N nor Q-F). 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 welds better, Q550-N or Q550 Q-F?

Q550 Q-F. Its weldability rates good (68/100) against good (62/100) for Q550-N.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Q550-N and Q550 Q-F 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.