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Steel 4150 vs 50B50

Steel · grade comparison

Steel 4150 and 50B50 are both steel grades. 4150 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 380 MPa (55.1 ksi) for 50B50, about 37% more; tensile strength follows at 860 MPa (125 ksi) vs 700 MPa (102 ksi). In exchange, 50B50 is the more ductile: elongation 21% versus 16% for 4150, and 4150 is harder (235 HB vs 197 HB). On the shop floor, 50B50 sits in a lower cost tier (budget, $) than 4150 (premium, $$$).

4150Choose it when strength drives the design.

50B50Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.

4150 vs 50B50: properties

415050B50

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

860 MPa125 ksi
700 MPa102 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
380 MPa55.1 ksi

Elongation at Break

16%
21%

Reduction in Area

40%
45%

Shear Strength

560 MPa81.2 ksi
430 MPa62.4 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
330 MPa47.9 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

235 HB
197 HB

Hardness, Rockwell C

21 HRC
—

Hardness, Vickers

245 HV
207 HV

Compressive Strength

—
380 MPa55.1 ksi

Fracture Toughness (K_IC)

—
90 MPa·√m81.9 ksi·√in

Hardness, Rockwell B

—
92 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

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,416°C2,581 °F
1,420°C2,588 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,490°C2,714 °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
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

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F

Min Service Temperature

-40°C-40 °F
-30°C-22 °F

Same in both: Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · 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).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

45 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
60%

Formability (cold)

25 / 100
45 / 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
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.2 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
89 kN·m/kg

Modulus of Resilience

660 kJ/m³
352 kJ/m³

Thermal Diffusivity

11.5 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

15
13

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 scale415050B50

Manufacturing and finishing

Capability415050B50
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$$$ Premium$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

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

4150 vs 50B50 — frequently asked

Is 4150 stronger than 50B50?

Yes. 4150 has a typical yield strength of 520 MPa (75.4 ksi) against 380 MPa (55.1 ksi) for 50B50 — about 37% more. Tensile strength is 860 MPa (125 ksi) vs 700 MPa (102 ksi).

Which is cheaper, 4150 or 50B50?

50B50 is the lower-cost material: it sits in the budget 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 50B50?

50B50, by a small margin. Both rate fair for machinability — 52/100 against 45/100 for 4150.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and 50B50 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.