FabDigitFabDigit

Steel 18NiCrMo14-6 vs 55Cr3

Steel · grade comparison

Steel 18NiCrMo14-6 and 55Cr3 are both steel grades. 55Cr3 is the stronger of the two: tensile strength 800 MPa (116 ksi) against 750 MPa (109 ksi) for 18NiCrMo14-6, about 7% more. 55Cr3 runs hotter in service (400°C vs 200°C continuous) and 55Cr3 conducts heat better (44 W/m·K vs 34 W/m·K). On the shop floor, 55Cr3 sits in a lower cost tier (standard, $$) than 18NiCrMo14-6 (premium, $$$).

55Cr3Choose it when strength drives the design, or when the part sees heat.

18NiCrMo14-6 vs 55Cr3: properties

18NiCrMo14-655Cr3

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
206 GPa29.9 Msi

Shear Modulus

80 GPa11.6 Msi
79.5 GPa11.5 Msi

Tensile Strength (Ultimate)

750 MPa109 ksi
800 MPa116 ksi

Yield Strength (0.2% offset)

500 MPa72.5 ksi
480 MPa69.6 ksi

Reduction in Area

45%
40%

Compressive Strength

760 MPa110 ksi
480 MPa69.6 ksi

Shear Strength

460 MPa66.7 ksi
500 MPa72.5 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
360 MPa52.2 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
85 MPa·√m77.4 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
30 J22.1 ft·lbf

Hardness, Brinell

220 HB
225 HB

Hardness, Rockwell B

96 HRB
98 HRB

Hardness, Vickers

230 HV
236 HV

Hardness, Rockwell C

—
20 HRC

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Elongation at Break 16%

Physical

Density and transition temperatures.

Liquidus Temperature

1,480°C2,696 °F
1,490°C2,714 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

34 W/m·K19.6 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Specific Heat Capacity

460 J/kg·K0.11 BTU/lb·°F
465 J/kg·K0.11 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

11.5 µm/m·K6.4 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

200°C392 °F
400°C752 °F

Min Service Temperature

-80°C-112 °F
-40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7 % IACS
7.8 % IACS

Electrical Resistivity

2.5×10⁻⁷ Ω·m9.84 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.65 V
—

Corrosion Resistance

12 / 100
10 / 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 %)

48%
55%

Castability

30 / 100
—

Brazeability / Solderability

45 / 100
40 / 100

Polishability

75 / 100
60 / 100

Same in both: Weldability 25 / 100 · Formability (cold) 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
26 MJ/kg11,178 BTU/lb

Embodied Carbon (primary production)

2.5 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

25%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

96 kN·m/kg
102 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

595 kJ/m³
559 kJ/m³

Thermal Diffusivity

9.4 mm²/s
12.1 mm²/s

Thermal Shock Resistance Index

11
14

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 scale55Cr318NiCrMo14-6

Manufacturing and finishing

Capability18NiCrMo14-655Cr3
CNC machining—Yes
Sheet metal—Yes
Default condition—Annealed
Relative cost$$$ Premium$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

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

18NiCrMo14-6 vs 55Cr3 — frequently asked

Is 55Cr3 stronger than 18NiCrMo14-6?

Yes. 55Cr3 has a typical tensile strength of 800 MPa (116 ksi) against 750 MPa (109 ksi) for 18NiCrMo14-6 — about 7% more.

Which is cheaper, 18NiCrMo14-6 or 55Cr3?

55Cr3 is the lower-cost material: it sits in the standard tier ($$) while 18NiCrMo14-6 is premium ($$$). 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, 18NiCrMo14-6 or 55Cr3?

55Cr3, by a small margin. Both rate fair for machinability — 50/100 against 45/100 for 18NiCrMo14-6.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 18NiCrMo14-6 and 55Cr3 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.