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Steel 4118 vs SCM415

Steel · grade comparison

Steel 4118 and SCM415 are both steel grades. SCM415 is the stronger of the two: yield strength 430 MPa (62.4 ksi) against 350 MPa (50.8 ksi) for 4118, about 23% more; tensile strength follows at 640 MPa (92.8 ksi) vs 530 MPa (76.9 ksi). In exchange, 4118 is the more ductile: elongation 26% versus 22% for SCM415, and SCM415 is harder (180 HB vs 149 HB). On the shop floor, 4118 sits in a lower cost tier (budget, $) than SCM415 (standard, $$).

4118Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.

SCM415Choose it when strength drives the design.

4118 vs SCM415: properties

4118SCM415

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
206 GPa29.9 Msi

Tensile Strength (Ultimate)

530 MPa76.9 ksi
640 MPa92.8 ksi

Yield Strength (0.2% offset)

350 MPa50.8 ksi
430 MPa62.4 ksi

Elongation at Break

26%
22%

Shear Strength

350 MPa50.8 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

240 MPa34.8 ksi
290 MPa42.1 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
90 MPa·√m81.9 ksi·√in

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

149 HB
180 HB

Hardness, Rockwell B

80 HRB
89 HRB

Compressive Strength

—
430 MPa62.4 ksi

Hardness, Vickers

—
190 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)

1,425°C2,597 °F
1,430°C2,606 °F

Liquidus Temperature

1,505°C2,741 °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.

Thermal Conductivity

42 W/m·K24.3 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

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)

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

Latent Heat of Fusion

247 J/g106 BTU/lb
250 J/g107 BTU/lb

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

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

-0.62 V
-0.61 V

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

60 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
60%

Weldability

60 / 100
55 / 100

Formability (cold)

65 / 100
60 / 100

Brazeability / Solderability

60 / 100
65 / 100

Polishability

50 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

24 MJ/kg10,318 BTU/lb
27 MJ/kg11,608 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
50 L/kg6 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

68 kN·m/kg
82 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

299 kJ/m³
449 kJ/m³

Thermal Diffusivity

11.3 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

9
11

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 scaleSCM4154118

Manufacturing and finishing

Capability4118SCM415
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

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

4118 vs SCM415 — frequently asked

Is SCM415 stronger than 4118?

Yes. SCM415 has a typical yield strength of 430 MPa (62.4 ksi) against 350 MPa (50.8 ksi) for 4118 — about 23% more. Tensile strength is 640 MPa (92.8 ksi) vs 530 MPa (76.9 ksi).

Which is cheaper, 4118 or SCM415?

4118 is the lower-cost material: it sits in the budget tier ($) while SCM415 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, 4118 or SCM415?

4118. Its weldability rates good (60/100) against good (55/100) for SCM415.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4118 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.