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Steel 4620 vs SNCM625

Steel · grade comparison

Steel 4620 and SNCM625 are both steel grades. SNCM625 is the stronger of the two: yield strength 880 MPa (128 ksi) against 360 MPa (52.2 ksi) for 4620, about 144% more; tensile strength follows at 1,000 MPa (145 ksi) vs 570 MPa (82.7 ksi). In exchange, 4620 is the more ductile: elongation 26% versus 20% for SNCM625, and SNCM625 is harder (290 HB vs 163 HB). 4620 conducts heat better (46 W/m·K vs 36 W/m·K). On the shop floor, 4620 machines more easily (good vs fair) and 4620 welds better (good vs poor).

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

SNCM625Choose it when strength drives the design.

4620 vs SNCM625: properties

4620SNCM625

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
206 GPa29.9 Msi

Tensile Strength (Ultimate)

570 MPa82.7 ksi
1,000 MPa145 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
880 MPa128 ksi

Elongation at Break

26%
20%

Shear Strength

380 MPa55.1 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

260 MPa37.7 ksi
470 MPa68.2 ksi

Charpy V-Notch Impact (RT)

85 J62.7 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

163 HB
290 HB

Hardness, Rockwell B

84 HRB
—

Compressive Strength

—
890 MPa129 ksi

Fracture Toughness (K_IC)

—
95 MPa·√m86.5 ksi·√in

Hardness, Rockwell C

—
30 HRC

Hardness, Vickers

—
305 HV

Same in both: 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.

Melting Point (Solidus)

1,420°C2,588 °F
1,425°C2,597 °F

Liquidus Temperature

1,500°C2,732 °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

46 W/m·K26.6 BTU/hr·ft·°F
36 W/m·K20.8 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.9 µm/m·K6.6 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
260 J/g112 BTU/lb

Min Service Temperature

-50°C-58 °F
-60°C-76 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7.2 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.4×10⁻⁷ Ω·m9.45 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
13 / 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%
50%

Weldability

65 / 100
25 / 100

Formability (cold)

58 / 100
22 / 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
34 MJ/kg14,617 BTU/lb

Embodied Carbon (primary production)

2.2 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)

73 kN·m/kg
127 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

316 kJ/m³
1,880 kJ/m³

Thermal Diffusivity

12.3 mm²/s
9.8 mm²/s

Thermal Shock Resistance Index

11
14

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 scale4620SNCM625

Manufacturing and finishing

Capability4620SNCM625
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.

4620 vs SNCM625 — frequently asked

Is SNCM625 stronger than 4620?

Yes. SNCM625 has a typical yield strength of 880 MPa (128 ksi) against 360 MPa (52.2 ksi) for 4620 — about 144% more. Tensile strength is 1,000 MPa (145 ksi) vs 570 MPa (82.7 ksi).

Which is cheaper, 4620 or SNCM625?

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, 4620 or SNCM625?

4620. Its machinability rates good (57/100) against fair (45/100) for SNCM625; for welding the order is 4620 first (good, 65/100) then SNCM625 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4620 and SNCM625 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.