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Steel 4150 vs 4615

Steel · grade comparison

Steel 4150 and 4615 are both steel grades. 4150 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 350 MPa (50.8 ksi) for 4615, about 49% more; tensile strength follows at 860 MPa (125 ksi) vs 560 MPa (81.2 ksi). In exchange, 4615 is the more ductile: elongation 25% versus 16% for 4150, and 4150 is harder (235 HB vs 163 HB). On the shop floor, 4615 machines more easily (good vs fair), 4615 welds better (good vs poor), and 4615 sits in a lower cost tier (standard, $$) than 4150 (premium, $$$).

4150Choose it when strength drives the design.

4615Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

4150 vs 4615: properties

41504615

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

860 MPa125 ksi
560 MPa81.2 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
350 MPa50.8 ksi

Elongation at Break

16%
25%

Reduction in Area

40%
55%

Shear Strength

560 MPa81.2 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
255 MPa37 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

235 HB
163 HB

Hardness, Rockwell C

21 HRC
—

Hardness, Vickers

245 HV
171 HV

Compressive Strength

—
350 MPa50.8 ksi

Fracture Toughness (K_IC)

—
100 MPa·√m91 ksi·√in

Hardness, Rockwell B

—
84 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
1,425°C2,597 °F

Liquidus Temperature

1,490°C2,714 °F
1,505°C2,741 °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
42 W/m·K24.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Min Service Temperature

-40°C-40 °F
-50°C-58 °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 · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
7.5 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2.3×10⁻⁷ Ω·m9.06 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-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

45 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
65%

Weldability

25 / 100
55 / 100

Formability (cold)

25 / 100
55 / 100

Castability

35 / 100
—

Brazeability / Solderability

55 / 100
70 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
45 L/kg5.4 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

110 kN·m/kg
71 kN·m/kg

Modulus of Resilience

660 kJ/m³
299 kJ/m³

Thermal Diffusivity

11.5 mm²/s
11.4 mm²/s

Thermal Shock Resistance Index

15
9

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 scale41504615

Manufacturing and finishing

Capability41504615
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 4615 — frequently asked

Is 4150 stronger than 4615?

Yes. 4150 has a typical yield strength of 520 MPa (75.4 ksi) against 350 MPa (50.8 ksi) for 4615 — about 49% more. Tensile strength is 860 MPa (125 ksi) vs 560 MPa (81.2 ksi).

Which is cheaper, 4150 or 4615?

4615 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 4615?

4615. Its machinability rates good (58/100) against fair (45/100) for 4150; for welding the order is 4615 first (good, 55/100) then 4150 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and 4615 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.