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Steel 4140 vs SCM435

Steel · grade comparison

Steel 4140 and SCM435 are both steel grades, both high strength steel. 4140 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 450 MPa (65.3 ksi) for SCM435, about 7% more.

4140Choose it when strength drives the design.

4140 vs SCM435: properties

4140SCM435

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
207 GPa30 Msi

Tensile Strength (Ultimate)

690 MPa100 ksi
700 MPa102 ksi

Yield Strength (0.2% offset)

480 MPa69.6 ksi
450 MPa65.3 ksi

Elongation at Break

22%
20%

Compressive Strength

480 MPa69.6 ksi
460 MPa66.7 ksi

Shear Strength

420 MPa60.9 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

345 MPa50 ksi
330 MPa47.9 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
75 MPa·√m68.3 ksi·√in

Hardness, Brinell

210 HB
207 HB

Hardness, Vickers

220 HV
217 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 50% · Charpy V-Notch Impact (RT) 40 J29.5 ft·lbf · Hardness, Rockwell B 94 HRB

Physical

Density and transition temperatures.

Liquidus Temperature

1,483°C2,701 °F
1,495°C2,723 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,416°C2,581 °F

Thermal

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

Thermal Conductivity

42.6 W/m·K24.6 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Max Service Temperature (continuous)

425°C797 °F
400°C752 °F

Same in both: Specific Heat Capacity 473 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °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)

-0.61 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

60 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
60%

Weldability

40 / 100
45 / 100

Formability (cold)

40 / 100
45 / 100

Polishability

60 / 100
65 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

32 MJ/kg13,758 BTU/lb
29 MJ/kg12,468 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

88 kN·m/kg
89 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.4 MN·m/kg

Modulus of Resilience

562 kJ/m³
489 kJ/m³

Thermal Diffusivity

11.5 mm²/s
11.3 mm²/s

Same in both: Thermal Shock Resistance Index 12

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 scale4140SCM435

Manufacturing and finishing

Capability4140SCM435
Casting & forgingYes—
Default conditionHRHR
Relative cost$$ Standard$$ 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.

4140 vs SCM435 — frequently asked

Is 4140 stronger than SCM435?

Yes. 4140 has a typical yield strength of 480 MPa (69.6 ksi) against 450 MPa (65.3 ksi) for SCM435 — about 7% more. Tensile strength is 690 MPa (100 ksi) vs 700 MPa (102 ksi).

Which is cheaper, 4140 or SCM435?

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, 4140 or SCM435?

4140, by a small margin. Both rate good for machinability — 60/100 against 55/100 for SCM435; for welding the order is SCM435 first (fair, 45/100) then 4140 (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4140 and SCM435 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.