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Steel 4620 vs SNCM815

Steel · grade comparison

Steel 4620 and SNCM815 are both steel grades. SNCM815 is the stronger of the two: yield strength 750 MPa (109 ksi) against 360 MPa (52.2 ksi) for 4620, about 108% more; tensile strength follows at 950 MPa (138 ksi) vs 570 MPa (82.7 ksi). In exchange, 4620 is the more ductile: elongation 26% versus 18% for SNCM815, and SNCM815 is harder (262 HB vs 163 HB). 4620 conducts heat better (46 W/m·K vs 34 W/m·K). On the shop floor, 4620 machines more easily (good vs fair), 4620 welds better (good vs poor), and 4620 sits in a lower cost tier (standard, $$) than SNCM815 (premium, $$$).

4620Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

SNCM815Choose it when strength drives the design.

4620 vs SNCM815: properties

4620SNCM815

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

570 MPa82.7 ksi
950 MPa138 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
750 MPa109 ksi

Elongation at Break

26%
18%

Shear Strength

380 MPa55.1 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

260 MPa37.7 ksi
450 MPa65.3 ksi

Charpy V-Notch Impact (RT)

85 J62.7 ft·lbf
65 J47.9 ft·lbf

Hardness, Brinell

163 HB
262 HB

Hardness, Rockwell B

84 HRB
—

Fracture Toughness (K_IC)

—
95 MPa·√m86.5 ksi·√in

Hardness, Rockwell C

—
26 HRC

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 · Reduction in Area 55%

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) 1,420°C2,588 °F

Thermal

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

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
34 W/m·K19.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.9 µm/m·K6.6 µin/in·°F
11.6 µm/m·K6.4 µin/in·°F

Latent Heat of Fusion

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

Min Service Temperature

-50°C-58 °F
-75°C-103 °F

Same in both: Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

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)

-0.61 V
-0.6 V

Corrosion Resistance

12 / 100
15 / 100

Manufacturability

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

Machinability

57 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
45%

Weldability

65 / 100
25 / 100

Formability (cold)

58 / 100
30 / 100

Brazeability / Solderability

70 / 100
45 / 100

Polishability

55 / 100
65 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

29 MJ/kg12,468 BTU/lb
36 MJ/kg15,477 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.6 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

73 kN·m/kg
121 kN·m/kg

Modulus of Resilience

316 kJ/m³
1,372 kJ/m³

Thermal Diffusivity

12.3 mm²/s
9.4 mm²/s

Thermal Shock Resistance Index

11
14

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg

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 scale4620SNCM815

Manufacturing and finishing

Capability4620SNCM815
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$$ Standard$$$ Premium
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.

4620 vs SNCM815 — frequently asked

Is SNCM815 stronger than 4620?

Yes. SNCM815 has a typical yield strength of 750 MPa (109 ksi) against 360 MPa (52.2 ksi) for 4620 — about 108% more. Tensile strength is 950 MPa (138 ksi) vs 570 MPa (82.7 ksi).

Which is cheaper, 4620 or SNCM815?

4620 is the lower-cost material: it sits in the standard tier ($$) while SNCM815 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 4620 or SNCM815?

4620. Its machinability rates good (57/100) against fair (45/100) for SNCM815; for welding the order is 4620 first (good, 65/100) then SNCM815 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4620 and SNCM815 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.