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Steel SCM420 vs SNCM616

Steel · grade comparison

Steel SCM420 and SNCM616 are both steel grades. SNCM616 is the stronger of the two: tensile strength 700 MPa (102 ksi) against 660 MPa (95.7 ksi) for SCM420, about 6% more. SNCM616 is harder — 210 HB against 190 HB for SCM420 — which matters for wear surfaces and threads. SCM420 conducts heat better (42 W/m·K vs 35 W/m·K). On the shop floor, SCM420 machines more easily (good vs fair), SCM420 welds better (good vs poor), and SCM420 forms better (good vs fair).

SCM420Choose it when the part is machined in volume, or when it will be welded.

SNCM616Choose it when strength drives the design, or when surface hardness matters.

SCM420 vs SNCM616: properties

SCM420SNCM616

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
206 GPa29.9 Msi

Tensile Strength (Ultimate)

660 MPa95.7 ksi
700 MPa102 ksi

Yield Strength (0.2% offset)

440 MPa63.8 ksi
450 MPa65.3 ksi

Elongation at Break

22%
20%

Reduction in Area

52%
55%

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
340 MPa49.3 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
—

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

190 HB
210 HB

Hardness, Rockwell B

91 HRB
94 HRB

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Shear Strength 430 MPa62.4 ksi

Physical

Density and transition temperatures.

Liquidus Temperature

1,500°C2,732 °F
1,490°C2,714 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,425°C2,597 °F

Thermal

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

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
35 W/m·K20.2 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

12.2 µm/m·K6.8 µin/in·°F
11.7 µm/m·K6.5 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Min Service Temperature

-40°C-40 °F
-80°C-112 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.5×10⁻⁷ Ω·m9.84 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.62 V
-0.6 V

Corrosion Resistance

12 / 100
14 / 100

Manufacturability

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

Machinability

60 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
50%

Weldability

55 / 100
25 / 100

Formability (cold)

60 / 100
40 / 100

Brazeability / Solderability

65 / 100
50 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
32 MJ/kg13,758 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.4 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
60 L/kg7.2 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

84 kN·m/kg
89 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

468 kJ/m³
492 kJ/m³

Thermal Diffusivity

11.4 mm²/s
9.5 mm²/s

Thermal Shock Resistance Index

11
10

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 scaleSCM420SNCM616

Manufacturing and finishing

CapabilitySCM420SNCM616
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$$ Standard$$ Standard
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

SCM420 vs SNCM616 — frequently asked

Is SNCM616 stronger than SCM420?

Yes. SNCM616 has a typical tensile strength of 700 MPa (102 ksi) against 660 MPa (95.7 ksi) for SCM420 — about 6% more.

Which is cheaper, SCM420 or SNCM616?

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

Which is easier to machine, SCM420 or SNCM616?

SCM420. Its machinability rates good (60/100) against fair (45/100) for SNCM616; for welding the order is SCM420 first (good, 55/100) then SNCM616 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in SCM420 and SNCM616 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.