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Steel 4142 vs 4150

Steel · grade comparison

Steel 4142 and 4150 are both steel grades, both high strength steel. 4150 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 450 MPa (65.3 ksi) for 4142, about 16% more; tensile strength follows at 860 MPa (125 ksi) vs 730 MPa (106 ksi). In exchange, 4142 is the more ductile: elongation 20% versus 16% for 4150, and 4150 is harder (235 HB vs 217 HB). On the shop floor, 4142 welds better (fair vs poor) and 4142 sits in a lower cost tier (standard, $$) than 4150 (premium, $$$).

4142Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

4150Choose it when strength drives the design.

4142 vs 4150: properties

41424150

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

730 MPa106 ksi
860 MPa125 ksi

Yield Strength (0.2% offset)

450 MPa65.3 ksi
520 MPa75.4 ksi

Elongation at Break

20%
16%

Reduction in Area

45%
40%

Compressive Strength

455 MPa66 ksi
—

Shear Strength

440 MPa63.8 ksi
560 MPa81.2 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
390 MPa56.6 ksi

Fracture Toughness (K_IC)

80 MPa·√m72.8 ksi·√in
—

Charpy V-Notch Impact (RT)

30 J22.1 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

217 HB
235 HB

Hardness, Rockwell B

96 HRB
—

Hardness, Rockwell C

17 HRC
21 HRC

Hardness, Vickers

228 HV
245 HV

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

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) 1,416°C2,581 °F

Thermal

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

Same in both: Thermal Conductivity 42.6 W/m·K24.6 BTU/hr·ft·°F · 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 · Max Service Temperature (continuous) 400°C752 °F · 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

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

54 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

58%
50%

Weldability

40 / 100
25 / 100

Formability (cold)

42 / 100
25 / 100

Castability

—
35 / 100

Same in both: Brazeability / Solderability 55 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

29 MJ/kg12,468 BTU/lb
31 MJ/kg13,328 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

45 L/kg5.4 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)

93 kN·m/kg
110 kN·m/kg

Modulus of Resilience

494 kJ/m³
660 kJ/m³

Thermal Shock Resistance Index

12
15

Same in both: Specific Stiffness (E / density) 26.1 MN·m/kg · Thermal Diffusivity 11.5 mm²/s

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 scale41504142

Manufacturing and finishing

Capability41424150
Default conditionHRHR
Relative cost$$ Standard$$$ Premium
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.

4142 vs 4150 — frequently asked

Is 4150 stronger than 4142?

Yes. 4150 has a typical yield strength of 520 MPa (75.4 ksi) against 450 MPa (65.3 ksi) for 4142 — about 16% more. Tensile strength is 860 MPa (125 ksi) vs 730 MPa (106 ksi).

Which is cheaper, 4142 or 4150?

4142 is the lower-cost material: it sits in the standard tier ($$) while 4150 is premium ($$$). 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, 4142 or 4150?

4142, by a small margin. Both rate fair for machinability — 54/100 against 45/100 for 4150; for welding the order is 4142 first (fair, 40/100) then 4150 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4142 and 4150 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.