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Steel SM520-N vs SM520 TMCP

Steel · SM520 temper comparison

SM520-N and SM520 TMCP are two conditions of the same steel grade, SM520: N (normalized) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 390 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (normalized versus thermomechanically controlled processed). SM520 TMCP is harder — 175 HB against 165 HB for SM520-N — which matters for wear surfaces and threads.

SM520 TMCPChoose it when surface hardness matters.

SM520-N vs SM520 TMCP: properties

SM520-NSM520 TMCP

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

555 MPa80.5 ksi
570 MPa82.7 ksi

Yield Strength (0.2% offset)

390 MPa56.6 ksi
410 MPa59.5 ksi

Reduction in Area

52%
55%

Compressive Strength

390 MPa56.6 ksi
410 MPa59.5 ksi

Shear Strength

360 MPa52.2 ksi
375 MPa54.4 ksi

Fatigue Strength (Endurance Limit)

255 MPa37 ksi
265 MPa38.4 ksi

Fracture Toughness (K_IC)

140 MPa·√m127 ksi·√in
170 MPa·√m155 ksi·√in

Charpy V-Notch Impact (RT)

130 J95.9 ft·lbf
180 J133 ft·lbf

Hardness, Brinell

165 HB
175 HB

Hardness, Rockwell B

85 HRB
88 HRB

Hardness, Vickers

173 HV
184 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Elongation at Break 24%

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 1,510°C2,750 °F

Thermal

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

Thermal Conductivity

50 W/m·K28.9 BTU/hr·ft·°F
49 W/m·K28.3 BTU/hr·ft·°F

Min Service Temperature

-30°C-22 °F
-40°C-40 °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) 350°C662 °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) -0.65 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

57 / 100
53 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
58%

Weldability

84 / 100
90 / 100

Formability (cold)

65 / 100
68 / 100

Same in both: Brazeability / Solderability 60 / 100 · 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 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 scaleSM520

SM520-N vs SM520 TMCP — frequently asked

What is the difference between SM520-N and SM520 TMCP?

SM520-N and SM520 TMCP are two conditions of the same steel grade, SM520: N (normalized) versus TMCP (thermomechanically controlled processed). The chemistry is identical, so every difference below comes from the condition. Both yield at about 390 MPa — the mechanical properties are the same, and the difference is in how the stock is processed and what it is certified to (normalized versus thermomechanically controlled processed).

Which condition does FabDigit quote by default, N or TMCP?

SM520B is the default SM520 condition in the FabDigit quote flow (neither N nor TMCP). 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, SM520-N or SM520 TMCP?

SM520 TMCP. Its weldability rates excellent (90/100) against very good (84/100) for SM520-N.

Ready to make it?

Upload a CAD file and FabDigit prices the part in SM520-N and SM520 TMCP 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.