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Steel 4150 vs 8630

Steel · grade comparison

Steel 4150 and 8630 are both steel grades. 4150 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 415 MPa (60.2 ksi) for 8630, about 25% more; tensile strength follows at 860 MPa (125 ksi) vs 690 MPa (100 ksi). In exchange, 8630 is the more ductile: elongation 22% versus 16% for 4150, and 4150 is harder (235 HB vs 197 HB). On the shop floor, 8630 machines more easily (good vs fair), 8630 welds better (fair vs poor), and 8630 sits in a lower cost tier (standard, $$) than 4150 (premium, $$$).

4150Choose it when strength drives the design.

8630Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

4150 vs 8630: properties

41508630

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

860 MPa125 ksi
690 MPa100 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
415 MPa60.2 ksi

Elongation at Break

16%
22%

Reduction in Area

40%
50%

Shear Strength

560 MPa81.2 ksi
450 MPa65.3 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
330 MPa47.9 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

235 HB
197 HB

Hardness, Rockwell C

21 HRC
—

Hardness, Vickers

245 HV
—

Hardness, Rockwell B

—
93 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
1,500°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
43 W/m·K24.8 BTU/hr·ft·°F

Specific Heat Capacity

473 J/kg·K0.11 BTU/lb·°F
477 J/kg·K0.11 BTU/lb·°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 · Max Service Temperature (continuous) 400°C752 °F

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
60 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
65%

Weldability

25 / 100
40 / 100

Formability (cold)

25 / 100
40 / 100

Castability

35 / 100
55 / 100

Polishability

60 / 100
55 / 100

Same in both: Brazeability / Solderability 55 / 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

Typical Recycled Content

30%
35%

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

110 kN·m/kg
88 kN·m/kg

Modulus of Resilience

660 kJ/m³
420 kJ/m³

Thermal Shock Resistance Index

15
12

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 scale41508630

Manufacturing and finishing

Capability41508630
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 8630 — frequently asked

Is 4150 stronger than 8630?

Yes. 4150 has a typical yield strength of 520 MPa (75.4 ksi) against 415 MPa (60.2 ksi) for 8630 — about 25% more. Tensile strength is 860 MPa (125 ksi) vs 690 MPa (100 ksi).

Which is cheaper, 4150 or 8630?

8630 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 8630?

8630. Its machinability rates good (60/100) against fair (45/100) for 4150; for welding the order is 8630 first (fair, 40/100) then 4150 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and 8630 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.