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Steel 4137 vs 4150

Steel · grade comparison

Steel 4137 and 4150 are both steel grades. 4137 is the stronger of the two: yield strength 860 MPa (125 ksi) against 520 MPa (75.4 ksi) for 4150, about 65% more; tensile strength follows at 965 MPa (140 ksi) vs 860 MPa (125 ksi). 4137 is the more ductile: elongation 18% versus 16% for 4150, and 4137 is harder (293 HB vs 235 HB). On the shop floor, 4137 welds better (fair vs poor) and 4137 sits in a lower cost tier (budget, $) than 4150 (premium, $$$).

4137Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

4137 vs 4150: properties

41374150

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

965 MPa140 ksi
860 MPa125 ksi

Yield Strength (0.2% offset)

860 MPa125 ksi
520 MPa75.4 ksi

Elongation at Break

18%
16%

Reduction in Area

55%
40%

Compressive Strength

870 MPa126 ksi
—

Shear Strength

580 MPa84.1 ksi
560 MPa81.2 ksi

Fatigue Strength (Endurance Limit)

470 MPa68.2 ksi
390 MPa56.6 ksi

Fracture Toughness (K_IC)

85 MPa·√m77.4 ksi·√in
—

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

293 HB
235 HB

Hardness, Rockwell C

30 HRC
21 HRC

Hardness, Vickers

305 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

1,495°C2,723 °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.

Latent Heat of Fusion

247 J/g106 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

370°C698 °F
400°C752 °F

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 · 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

52 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

55%
50%

Weldability

40 / 100
25 / 100

Formability (cold)

30 / 100
25 / 100

Polishability

70 / 100
60 / 100

Castability

—
35 / 100

Same in both: Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
31 MJ/kg13,328 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2.3 kg CO₂/kg

Typical Recycled Content

35%
30%

Same in both: Embodied Water 60 L/kg7.2 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

123 kN·m/kg
110 kN·m/kg

Modulus of Resilience

1,804 kJ/m³
660 kJ/m³

Thermal Shock Resistance Index

16
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 scale41504137

Manufacturing and finishing

Capability41374150
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$$$ Premium
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

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

4137 vs 4150 — frequently asked

Is 4137 stronger than 4150?

Yes. 4137 has a typical yield strength of 860 MPa (125 ksi) against 520 MPa (75.4 ksi) for 4150 — about 65% more. Tensile strength is 965 MPa (140 ksi) vs 860 MPa (125 ksi).

Which is cheaper, 4137 or 4150?

4137 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, 4137 or 4150?

4137, by a small margin. Both rate fair for machinability — 52/100 against 45/100 for 4150; for welding the order is 4137 first (fair, 40/100) then 4150 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4137 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.