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Steel SCM422 vs SNCM447

Steel · grade comparison

Steel SCM422 and SNCM447 are both steel grades. SNCM447 is the stronger of the two: yield strength 980 MPa (142 ksi) against 370 MPa (53.7 ksi) for SCM422, about 165% more; tensile strength follows at 1,100 MPa (160 ksi) vs 580 MPa (84.1 ksi). In exchange, SCM422 is the more ductile: elongation 25% versus 16% for SNCM447, and SNCM447 is harder (325 HB vs 170 HB). SNCM447 runs hotter in service (400°C vs 350°C continuous) and SCM422 conducts electricity better (8 % IACS vs 7 % IACS). On the shop floor, SCM422 machines more easily (good vs fair) and SCM422 welds better (fair vs poor).

SCM422Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

SNCM447Choose it when strength drives the design, or when the part sees heat.

SCM422 vs SNCM447: properties

SCM422SNCM447

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

206 GPa29.9 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

580 MPa84.1 ksi
1,100 MPa160 ksi

Yield Strength (0.2% offset)

370 MPa53.7 ksi
980 MPa142 ksi

Elongation at Break

25%
16%

Reduction in Area

55%
48%

Shear Strength

360 MPa52.2 ksi
660 MPa95.7 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
520 MPa75.4 ksi

Hardness, Brinell

170 HB
325 HB

Hardness, Rockwell B

87 HRB
—

Compressive Strength

—
990 MPa144 ksi

Fracture Toughness (K_IC)

—
90 MPa·√m81.9 ksi·√in

Hardness, Rockwell C

—
34 HRC

Hardness, Vickers

—
340 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Charpy V-Notch Impact (RT) 45 J33.2 ft·lbf

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,500°C2,732 °F
1,490°C2,714 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³

Thermal

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

Specific Heat Capacity

470 J/kg·K0.11 BTU/lb·°F
475 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

12.2 µm/m·K6.8 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Same in both: Thermal Conductivity 42 W/m·K24.3 BTU/hr·ft·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.48×10⁻⁷ Ω·m9.76 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 100
12 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

55 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
45%

Weldability

40 / 100
25 / 100

Formability (cold)

55 / 100
25 / 100

Brazeability / Solderability

55 / 100
45 / 100

Polishability

60 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
30 MJ/kg12,898 BTU/lb

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

74 kN·m/kg
140 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

332 kJ/m³
2,342 kJ/m³

Thermal Diffusivity

11.4 mm²/s
11.3 mm²/s

Thermal Shock Resistance Index

10
18

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 scaleSCM422SNCM447

Manufacturing and finishing

CapabilitySCM422SNCM447
Default condition——
Relative cost$ Budget$ Budget
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

SCM422 vs SNCM447 — frequently asked

Is SNCM447 stronger than SCM422?

Yes. SNCM447 has a typical yield strength of 980 MPa (142 ksi) against 370 MPa (53.7 ksi) for SCM422 — about 165% more. Tensile strength is 1,100 MPa (160 ksi) vs 580 MPa (84.1 ksi).

Which is cheaper, SCM422 or SNCM447?

Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, SCM422 or SNCM447?

SCM422. Its machinability rates good (55/100) against fair (42/100) for SNCM447; for welding the order is SCM422 first (fair, 40/100) then SNCM447 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SCM422 and SNCM447 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.