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Steel 4150 vs 5150

Steel · grade comparison

Steel 4150 and 5150 are both steel grades. 4150 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 460 MPa (66.7 ksi) for 5150, about 13% more; tensile strength follows at 860 MPa (125 ksi) vs 800 MPa (116 ksi). In exchange, 5150 is the more ductile: elongation 18% versus 16% for 4150. 4150 runs hotter in service (400°C vs 300°C continuous). On the shop floor, 5150 sits in a lower cost tier (standard, $$) than 4150 (premium, $$$).

4150Choose it when strength drives the design, or when the part sees heat.

5150Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.

4150 vs 5150: properties

41505150

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

860 MPa125 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
460 MPa66.7 ksi

Elongation at Break

16%
18%

Reduction in Area

40%
42%

Shear Strength

560 MPa81.2 ksi
490 MPa71.1 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
370 MPa53.7 ksi

Hardness, Brinell

235 HB
229 HB

Hardness, Rockwell C

21 HRC
20 HRC

Hardness, Vickers

245 HV
240 HV

Compressive Strength

—
460 MPa66.7 ksi

Hardness, Rockwell B

—
98 HRB

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 · Charpy V-Notch Impact (RT) 25 J18.4 ft·lbf

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,416°C2,581 °F
1,420°C2,588 °F

Liquidus Temperature

1,490°C2,714 °F
1,465°C2,669 °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

42.6 W/m·K24.6 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.3 µm/m·K6.8 µin/in·°F
12.4 µm/m·K6.9 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
300°C572 °F

Min Service Temperature

-40°C-40 °F
-30°C-22 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
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

Same in both: Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

45 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
55%

Formability (cold)

25 / 100
35 / 100

Castability

35 / 100
—

Same in both: Weldability 25 / 100 · Brazeability / Solderability 55 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2 kg CO₂/kg

Same in both: Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

110 kN·m/kg
102 kN·m/kg

Modulus of Resilience

660 kJ/m³
516 kJ/m³

Thermal Diffusivity

11.5 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

15
14

Same in both: Specific Stiffness (E / density) 26.1 MN·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 scale41505150

Manufacturing and finishing

Capability41505150
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.

4150 vs 5150 — frequently asked

Is 4150 stronger than 5150?

Yes. 4150 has a typical yield strength of 520 MPa (75.4 ksi) against 460 MPa (66.7 ksi) for 5150 — about 13% more. Tensile strength is 860 MPa (125 ksi) vs 800 MPa (116 ksi).

Which is cheaper, 4150 or 5150?

5150 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, 4150 or 5150?

5150, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for 4150.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and 5150 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.