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Steel Q550 M-E vs Q550-N

Steel · Q550 temper comparison

Q550 M-E and Q550-N are two conditions of the same steel grade, Q550: M-E (Q550ME) versus N (normalized). The chemistry is identical, so every difference below comes from the condition. Both yield at about 595 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (Q550ME versus normalized). Q550 M-E is the more ductile: elongation 19% versus 17% for Q550-N, and Q550 M-E is harder (21 HRC vs 18 HRC). Q550-N runs hotter in service (400°C vs 350°C continuous). On the shop floor, Q550 M-E welds better (very good vs good).

Q550 M-EChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

Q550-NChoose it when the part sees heat.

Q550 M-E vs Q550-N: properties

Q550 M-EQ550-N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

730 MPa106 ksi
700 MPa102 ksi

Yield Strength (0.2% offset)

595 MPa86.3 ksi
575 MPa83.4 ksi

Elongation at Break

19%
17%

Reduction in Area

56%
55%

Compressive Strength

595 MPa86.3 ksi
575 MPa83.4 ksi

Shear Strength

440 MPa63.8 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
315 MPa45.7 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

140 J103 ft·lbf
100 J73.8 ft·lbf

Hardness, Brinell

225 HB
215 HB

Hardness, Rockwell B

98 HRB
96 HRB

Hardness, Rockwell C

21 HRC
18 HRC

Hardness, Vickers

235 HV
225 HV

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

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

42 W/m·K24.3 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-40°C-40 °F
-20°C-4 °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

Electrical

Conductivity and insulation.

Electrical Conductivity

7.5 % IACS
7.8 % IACS

Electrical Resistivity

2.3×10⁻⁷ Ω·m9.06 µΩ·in
2.2×10⁻⁷ Ω·m8.66 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

45 / 100
48 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
53%

Weldability

72 / 100
62 / 100

Formability (cold)

52 / 100
55 / 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 M-E vs Q550-N — frequently asked

What is the difference between Q550 M-E and Q550-N?

Q550 M-E and Q550-N are two conditions of the same steel grade, Q550: M-E (Q550ME) versus N (normalized). The chemistry is identical, so every difference below comes from the condition. Both yield at about 595 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (Q550ME versus normalized).

Which condition does FabDigit quote by default, M-E or N?

M-D is the default Q550 condition in the FabDigit quote flow (neither M-E 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 welds better, Q550 M-E or Q550-N?

Q550 M-E. Its weldability rates very good (72/100) against good (62/100) for Q550-N.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Q550 M-E and Q550-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.