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Steel 4150 vs DP780

Steel · grade comparison

Steel 4150 and DP780 are both steel grades, both high strength steel. Both yield at about 520 MPa — strength does not separate them. DP780 is harder — 24 HRC against 21 HRC for 4150 — which matters for wear surfaces and threads. 4150 runs hotter in service (400°C vs 250°C continuous). On the shop floor, DP780 welds better (very good vs poor), DP780 forms better (good vs poor), and DP780 sits in a lower cost tier (standard, $$) than 4150 (premium, $$$).

4150Choose it when the part sees heat.

DP780Choose it when surface hardness matters, or when it will be welded.

4150 vs DP780: properties

4150DP780

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
207 GPa30 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

860 MPa125 ksi
830 MPa120 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
500 MPa72.5 ksi

Reduction in Area

40%
—

Shear Strength

560 MPa81.2 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

390 MPa56.6 ksi
380 MPa55.1 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
—

Hardness, Brinell

235 HB
245 HB

Hardness, Rockwell C

21 HRC
24 HRC

Hardness, Vickers

245 HV
255 HV

Compressive Strength

—
510 MPa74 ksi

Hardness, Rockwell B

—
99 HRB

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Elongation at Break 16%

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,416°C2,581 °F
1,490°C2,714 °F

Liquidus Temperature

1,490°C2,714 °F
1,520°C2,768 °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
40 W/m·K23.1 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

12.3 µm/m·K6.8 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Same in both: Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.8 % IACS
8.6 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
2×10⁻⁷ Ω·m7.87 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
10 / 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
42 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
45%

Weldability

25 / 100
72 / 100

Formability (cold)

25 / 100
55 / 100

Castability

35 / 100
—

Brazeability / Solderability

55 / 100
45 / 100

Polishability

60 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

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

Embodied Water

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

Typical Recycled Content

30%
25%

Same in both: Embodied Carbon (primary production) 2.3 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

110 kN·m/kg
106 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.4 MN·m/kg

Modulus of Resilience

660 kJ/m³
604 kJ/m³

Thermal Diffusivity

11.5 mm²/s
10.8 mm²/s

Thermal Shock Resistance Index

15
13

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 scale4150DP780

Manufacturing and finishing

Capability4150DP780
CNC machiningYes—
Default conditionHRCR
Relative cost$$$ Premium$$ Standard
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CrNYes—
DLCYes—
HVOF CoatingYes—
MoS2Yes—
Multilayer CVDYes—
TiAlNYes—
TiB2Yes—
TiCNYes—
TiNYes—
WC/CYes—
ZrNYes—

Both are offered for Sheet metal. They share 22 finishes: Black Oxide, Cerakote, Chrome Plating, Copper Plating, E-Coating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Hot-Dip Galvanizing, Manganese Phosphate, Nickel Plating and 10 more.

4150 vs DP780 — frequently asked

What is the difference between 4150 and DP780?

Steel 4150 and DP780 are both steel grades, both high strength steel. Both yield at about 520 MPa — strength does not separate them. DP780 is harder — 24 HRC against 21 HRC for 4150 — which matters for wear surfaces and threads.

Which is cheaper, 4150 or DP780?

DP780 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 welds better, 4150 or DP780?

DP780. Its weldability rates very good (72/100) against poor (25/100) for 4150.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 4150 and DP780 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.