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Steel 4150 vs 8637

Steel · grade comparison

Steel 4150 and 8637 are both steel grades. 8637 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). 8637 is the more ductile: elongation 19% versus 16% for 4150, and 8637 is harder (285 HB vs 235 HB). On the shop floor, 8637 welds better (fair vs poor) and 8637 sits in a lower cost tier (budget, $) than 4150 (premium, $$$).

8637Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

4150 vs 8637: properties

41508637

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

860 MPa125 ksi
965 MPa140 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
860 MPa125 ksi

Elongation at Break

16%
19%

Reduction in Area

40%
58%

Shear Strength

560 MPa81.2 ksi
610 MPa88.5 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
450 MPa65.3 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

235 HB
285 HB

Hardness, Rockwell C

21 HRC
30 HRC

Hardness, Vickers

245 HV
300 HV

Compressive Strength

—
870 MPa126 ksi

Fracture Toughness (K_IC)

—
90 MPa·√m81.9 ksi·√in

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

Liquidus Temperature

1,490°C2,714 °F
1,500°C2,732 °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
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Same in both: 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.

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
-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%

Weldability

25 / 100
35 / 100

Castability

35 / 100
—

Polishability

60 / 100
65 / 100

Same in both: Formability (cold) 25 / 100 · Brazeability / Solderability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
34 MJ/kg14,617 BTU/lb

Embodied Carbon (primary production)

2.3 kg CO₂/kg
2.4 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
65 L/kg7.8 gal/lb

Typical Recycled Content

30%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

110 kN·m/kg
123 kN·m/kg

Modulus of Resilience

660 kJ/m³
1,804 kJ/m³

Thermal Diffusivity

11.5 mm²/s
11.8 mm²/s

Thermal Shock Resistance Index

15
17

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 scale41508637

Manufacturing and finishing

Capability41508637
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 8637 — frequently asked

Is 8637 stronger than 4150?

Yes. 8637 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, 4150 or 8637?

8637 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 8637?

8637, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for 4150; for welding the order is 8637 first (fair, 35/100) then 4150 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and 8637 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.