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Steel 4320 vs SCM415

Steel · grade comparison

Steel 4320 and SCM415 are both steel grades, both case hardening steel. Both yield at about 415 MPa — strength does not separate them. SCM415 runs hotter in service (400°C vs 350°C continuous). On the shop floor, SCM415 welds better (good vs fair), SCM415 forms better (good vs fair), and SCM415 sits in a lower cost tier (standard, $$) than 4320 (premium, $$$).

SCM415Choose it when the part sees heat, or when it will be welded.

4320 vs SCM415: properties

4320SCM415

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
206 GPa29.9 Msi

Yield Strength (0.2% offset)

415 MPa60.2 ksi
430 MPa62.4 ksi

Reduction in Area

50%
55%

Shear Strength

415 MPa60.2 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

300 MPa43.5 ksi
290 MPa42.1 ksi

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

187 HB
180 HB

Hardness, Rockwell B

90 HRB
89 HRB

Compressive Strength

—
430 MPa62.4 ksi

Fracture Toughness (K_IC)

—
90 MPa·√m81.9 ksi·√in

Hardness, Vickers

—
190 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Tensile Strength (Ultimate) 640 MPa92.8 ksi · Elongation at Break 22%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,430°C2,606 °F

Liquidus Temperature

1,500°C2,732 °F
1,510°C2,750 °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

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

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

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

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-60°C-76 °F
-50°C-58 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

—
7.8 % IACS

Same in both: 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
-0.61 V

Corrosion Resistance

11 / 100
12 / 100

Manufacturability

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

Machinability

50 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
60%

Weldability

40 / 100
55 / 100

Formability (cold)

45 / 100
60 / 100

Brazeability / Solderability

55 / 100
65 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
27 MJ/kg11,608 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.1 kg CO₂/kg

Same in both: Embodied Water 50 L/kg6 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Stiffness (E / density)

26.1 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

420 kJ/m³
449 kJ/m³

Thermal Diffusivity

11.8 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

12
11

Same in both: Specific Strength (UTS / density) 82 kN·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 scaleSCM4154320

Manufacturing and finishing

Capability4320SCM415
Default conditionHRHR
Relative cost$$$ Premium$$ Standard
Min. machined wall0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µm

Both are offered for CNC machining and Sheet metal. Both take the same 38 finishes: AlCrN, AlTiN, Black Oxide, CVD Al2O3, CVD TiCN, CVD TiN, Cerakote, Chrome Plating, Copper Plating, CrN, DLC, E-Coating and 26 more.

4320 vs SCM415 — frequently asked

What is the difference between 4320 and SCM415?

Steel 4320 and SCM415 are both steel grades, both case hardening steel. Both yield at about 415 MPa — strength does not separate them. SCM415 runs hotter in service (400°C vs 350°C continuous).

Which is cheaper, 4320 or SCM415?

SCM415 is the lower-cost material: it sits in the standard tier ($$) while 4320 is premium ($$$). 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, 4320 or SCM415?

SCM415. Its machinability rates good (58/100) against fair (50/100) for 4320; for welding the order is SCM415 first (good, 55/100) then 4320 (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4320 and SCM415 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.