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Steel SCM432-N vs SCM432 QT 40-45 HRC

Steel · SCM432 temper comparison

SCM432-N and SCM432 QT 40-45 HRC are two conditions of the same steel grade, SCM432: N (normalized) versus QT 40-45 HRC. The chemistry is identical, so every difference below comes from the condition. SCM432 QT 40-45 HRC is the stronger of the two: yield strength 1,250 MPa (181 ksi) against 470 MPa (68.2 ksi) for SCM432-N, about 166% more; tensile strength follows at 1,400 MPa (203 ksi) vs 740 MPa (107 ksi). In exchange, SCM432-N is the more ductile: elongation 20% versus 11% for SCM432 QT 40-45 HRC, and SCM432 QT 40-45 HRC is harder (400 HB vs 217 HB). SCM432-N runs hotter in service (400°C vs 200°C continuous). On the shop floor, SCM432-N machines more easily (good vs poor).

SCM432-NChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

SCM432 QT 40-45 HRCChoose it when strength drives the design.

SCM432-N vs SCM432 QT 40-45 HRC: properties

SCM432-NSCM432 QT 40-45 HRC

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

740 MPa107 ksi
1,400 MPa203 ksi

Yield Strength (0.2% offset)

470 MPa68.2 ksi
1,250 MPa181 ksi

Elongation at Break

20%
11%

Reduction in Area

52%
42%

Compressive Strength

480 MPa69.6 ksi
860 MPa125 ksi

Shear Strength

445 MPa64.5 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
620 MPa89.9 ksi

Fracture Toughness (K_IC)

75 MPa·√m68.3 ksi·√in
60 MPa·√m54.6 ksi·√in

Charpy V-Notch Impact (RT)

50 J36.9 ft·lbf
28 J20.7 ft·lbf

Hardness, Brinell

217 HB
400 HB

Hardness, Rockwell C

17 HRC
42 HRC

Hardness, Vickers

228 HV
420 HV

Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 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) 1,420°C2,588 °F · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

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

Max Service Temperature (continuous)

400°C752 °F
200°C392 °F

Same in both: Specific Heat Capacity 473 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.2 % IACS
7.8 % IACS

Electrical Resistivity

2.1×10⁻⁷ Ω·m8.27 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

60 / 100
32 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
32%

Weldability

50 / 100
45 / 100

Formability (cold)

48 / 100
40 / 100

Same in both: Brazeability / Solderability 55 / 100 · Polishability 65 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 28 MJ/kg12,038 BTU/lb · Embodied Carbon (primary production) 2.1 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 scaleSCM432

SCM432-N vs SCM432 QT 40-45 HRC — frequently asked

Is SCM432 QT 40-45 HRC stronger than SCM432-N?

Yes. SCM432 QT 40-45 HRC has a typical yield strength of 1,250 MPa (181 ksi) against 470 MPa (68.2 ksi) for SCM432-N — about 166% more. Tensile strength is 1,400 MPa (203 ksi) vs 740 MPa (107 ksi).

Which condition does FabDigit quote by default, N or QT 40-45 HRC?

QT is the default SCM432 condition in the FabDigit quote flow (neither N nor QT 40-45 HRC). 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, SCM432-N or SCM432 QT 40-45 HRC?

SCM432-N. Its machinability rates good (60/100) against poor (32/100) for SCM432 QT 40-45 HRC; for welding the order is SCM432-N first (fair, 50/100) then SCM432 QT 40-45 HRC (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SCM432-N and SCM432 QT 40-45 HRC 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.