FabDigit

5155 vs 4140 and 2 more: properties

5155414041505160

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,600 MPa232 ksi
690 MPa100 ksi
860 MPa125 ksi
725 MPa105 ksi

Yield Strength (0.2% offset)

1,420 MPa206 ksi
480 MPa69.6 ksi
520 MPa75.4 ksi
275 MPa39.9 ksi

Elongation at Break

10%
22%
16%
17%

Reduction in Area

35%
50%
40%
31%

Compressive Strength

1,450 MPa210 ksi
480 MPa69.6 ksi

Shear Strength

960 MPa139 ksi
420 MPa60.9 ksi
560 MPa81.2 ksi
450 MPa65.3 ksi

Fatigue Strength (Endurance Limit)

750 MPa109 ksi
345 MPa50 ksi
390 MPa56.6 ksi
330 MPa47.9 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

14 J10.3 ft·lbf
40 J29.5 ft·lbf
25 J18.4 ft·lbf
25 J18.4 ft·lbf

Hardness, Brinell

435 HB
210 HB
235 HB
197 HB

Hardness, Rockwell C

46 HRC
21 HRC

Hardness, Vickers

460 HV
220 HV
245 HV

Hardness, Rockwell B

94 HRB
92 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)

1,420°C2,588 °F
1,416°C2,581 °F
1,416°C2,581 °F
1,425°C2,597 °F

Liquidus Temperature

1,480°C2,696 °F
1,483°C2,701 °F
1,490°C2,714 °F
1,490°C2,714 °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

45 W/m·K26 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F
42.6 W/m·K24.6 BTU/hr·ft·°F
46 W/m·K26.6 BTU/hr·ft·°F

Specific Heat Capacity

475 J/kg·K0.11 BTU/lb·°F
473 J/kg·K0.11 BTU/lb·°F
473 J/kg·K0.11 BTU/lb·°F
490 J/kg·K0.12 BTU/lb·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

250°C482 °F
425°C797 °F
400°C752 °F
250°C482 °F

Same in both: 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
-0.61 V
-0.6 V
-0.61 V

Corrosion Resistance

12 / 100
12 / 100
12 / 100
10 / 100

Manufacturability

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

Machinability

30 / 100
60 / 100
45 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
62%
50%
56%

Weldability

20 / 100
40 / 100
25 / 100
25 / 100

Formability (cold)

15 / 100
40 / 100
25 / 100
45 / 100

Brazeability / Solderability

30 / 100
55 / 100
55 / 100
55 / 100

Polishability

65 / 100
60 / 100
60 / 100
70 / 100

Castability

35 / 100
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
32 MJ/kg13,758 BTU/lb
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
2.3 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

55 L/kg6.6 gal/lb
55 L/kg6.6 gal/lb
60 L/kg7.2 gal/lb
60 L/kg7.2 gal/lb

Typical Recycled Content

30%
30%
30%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

204 kN·m/kg
88 kN·m/kg
110 kN·m/kg
92 kN·m/kg

Modulus of Resilience

4,918 kJ/m³
562 kJ/m³
660 kJ/m³
184 kJ/m³

Thermal Diffusivity

12.1 mm²/s
11.5 mm²/s
11.5 mm²/s
12 mm²/s

Thermal Shock Resistance Index

29
12
15
13

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 scale4140415051605155

Manufacturing and finishing

Capability5155414041505160
CNC machiningYesYesYes
Sheet metalYesYesYes
Casting & forgingYes
Default conditionHRHRAnnealed
Relative cost$ Budget$$ Standard$$$ Premium$$$ Premium
Min. machined wall0.8 mm0.8 mm0.8 mm
Best machined surfaceRa 1.6 µmRa 1.6 µmRa 1.6 µm
AlCrNYesYesYes
AlTiNYesYesYes
Black OxideYesYesYes
CVD Al2O3YesYesYes
CVD TiCNYesYesYes
CVD TiNYesYesYes
CerakoteYesYesYes
Chrome PlatingYesYesYes
CrNYesYesYes
DLCYesYesYes
E-CoatingYesYesYes
HVOF CoatingYesYesYes
Hot-Dip GalvanizingYesYesYes
MoS2YesYesYes
Multilayer CVDYesYesYes
Nickel PlatingYesYesYes
PTFE CoatingYesYesYes
PaintingYesYesYes

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

Ready to make it?

Upload a CAD file and FabDigit prices the part in 5155 and 4140 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.