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Steel SCM445 vs SNCM240

Steel · grade comparison

Steel SCM445 and SNCM240 are both steel grades. SCM445 is the stronger of the two: yield strength 950 MPa (138 ksi) against 820 MPa (119 ksi) for SNCM240, about 16% more; tensile strength follows at 1,130 MPa (164 ksi) vs 1,000 MPa (145 ksi). In exchange, SNCM240 is the more ductile: elongation 17% versus 14% for SCM445, and SCM445 is harder (330 HB vs 285 HB). On the shop floor, SNCM240 machines more easily (50 vs 40 out of 100) and SNCM240 welds better (fair vs poor).

SCM445Choose it when strength drives the design.

SNCM240Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

SCM445 vs SNCM240: properties

SCM445SNCM240

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
205 GPa29.7 Msi

Tensile Strength (Ultimate)

1,130 MPa164 ksi
1,000 MPa145 ksi

Yield Strength (0.2% offset)

950 MPa138 ksi
820 MPa119 ksi

Elongation at Break

14%
17%

Reduction in Area

48%
52%

Compressive Strength

960 MPa139 ksi
830 MPa120 ksi

Shear Strength

680 MPa98.6 ksi
610 MPa88.5 ksi

Fatigue Strength (Endurance Limit)

500 MPa72.5 ksi
470 MPa68.2 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
90 MPa·√m81.9 ksi·√in

Charpy V-Notch Impact (RT)

35 J25.8 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

330 HB
285 HB

Hardness, Rockwell C

35 HRC
30 HRC

Hardness, Vickers

345 HV
300 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Liquidus Temperature

1,490°C2,714 °F
1,495°C2,723 °F

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

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
43 W/m·K24.8 BTU/hr·ft·°F

Specific Heat Capacity

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

Same in both: Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.65 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

40 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
55%

Weldability

25 / 100
35 / 100

Formability (cold)

20 / 100
30 / 100

Brazeability / Solderability

45 / 100
55 / 100

Polishability

65 / 100
60 / 100

Castability

—
25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
29 MJ/kg12,468 BTU/lb

Embodied Water

45 L/kg5.4 gal/lb
55 L/kg6.6 gal/lb

Typical Recycled Content

30%
25%

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

144 kN·m/kg
127 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.1 MN·m/kg

Modulus of Resilience

2,180 kJ/m³
1,640 kJ/m³

Thermal Diffusivity

11.4 mm²/s
11.5 mm²/s

Thermal Shock Resistance Index

19
17

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 scaleSCM445SNCM240

Manufacturing and finishing

CapabilitySCM445SNCM240
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.

SCM445 vs SNCM240 — frequently asked

Is SCM445 stronger than SNCM240?

Yes. SCM445 has a typical yield strength of 950 MPa (138 ksi) against 820 MPa (119 ksi) for SNCM240 — about 16% more. Tensile strength is 1,130 MPa (164 ksi) vs 1,000 MPa (145 ksi).

Which is cheaper, SCM445 or SNCM240?

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, SCM445 or SNCM240?

SNCM240, by a small margin. Both rate fair for machinability — 50/100 against 40/100 for SCM445; for welding the order is SNCM240 first (fair, 35/100) then SCM445 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SCM445 and SNCM240 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.