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Steel 4150 vs 9255

Steel · grade comparison

Steel 4150 and 9255 are both steel grades. 9255 is the stronger of the two: yield strength 1,620 MPa (235 ksi) against 520 MPa (75.4 ksi) for 4150, about 3.1 times as much; tensile strength follows at 1,760 MPa (255 ksi) vs 860 MPa (125 ksi). In exchange, 4150 is the more ductile: elongation 16% versus 8% for 9255, and 9255 is harder (495 HB vs 235 HB). 4150 runs hotter in service (400°C vs 250°C continuous) and 4150 conducts electricity better (7.8 % IACS vs 5.7 % IACS). On the shop floor, 4150 machines more easily (fair vs poor), 4150 welds better (25 vs 15 out of 100), and 9255 sits in a lower cost tier (budget, $) than 4150 (premium, $$$).

4150Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

9255Choose it when strength drives the design, or when cost is the deciding factor.

4150 vs 9255: properties

41509255

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

80 GPa11.6 Msi
79 GPa11.5 Msi

Tensile Strength (Ultimate)

860 MPa125 ksi
1,760 MPa255 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
1,620 MPa235 ksi

Elongation at Break

16%
8%

Reduction in Area

40%
25%

Shear Strength

560 MPa81.2 ksi
1,060 MPa154 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
720 MPa104 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
14 J10.3 ft·lbf

Hardness, Brinell

235 HB
495 HB

Hardness, Rockwell C

21 HRC
50 HRC

Hardness, Vickers

245 HV
520 HV

Compressive Strength

—
1,650 MPa239 ksi

Fracture Toughness (K_IC)

—
40 MPa·√m36.4 ksi·√in

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Density

7.85 g/cm³0.28 lb/in³
7.8 g/cm³0.28 lb/in³

Melting Point (Solidus)

1,416°C2,581 °F
1,400°C2,552 °F

Liquidus Temperature

1,490°C2,714 °F
1,470°C2,678 °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
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
11.8 µm/m·K6.6 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
5.7 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
3×10⁻⁷ Ω·m11.8 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
11 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V

Manufacturability

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

Machinability

45 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
30%

Weldability

25 / 100
15 / 100

Formability (cold)

25 / 100
10 / 100

Castability

35 / 100
30 / 100

Brazeability / Solderability

55 / 100
30 / 100

Polishability

60 / 100
70 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg · 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
226 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.3 MN·m/kg

Modulus of Resilience

660 kJ/m³
6,401 kJ/m³

Thermal Diffusivity

11.5 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

15
32

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 scale41509255

Manufacturing and finishing

Capability41509255
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 9255 — frequently asked

Is 9255 stronger than 4150?

Yes. 9255 has a typical yield strength of 1,620 MPa (235 ksi) against 520 MPa (75.4 ksi) for 4150 — about 3.1 times as much. Tensile strength is 1,760 MPa (255 ksi) vs 860 MPa (125 ksi).

Which is cheaper, 4150 or 9255?

9255 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 9255?

4150. Its machinability rates fair (45/100) against poor (25/100) for 9255; for welding the order is 4150 first (poor, 25/100) then 9255 (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and 9255 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.