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Steel 18NiCrMo14-6 vs 34MnB5

Steel · grade comparison

Steel 18NiCrMo14-6 and 34MnB5 are both steel grades. 18NiCrMo14-6 is the stronger of the two: yield strength 500 MPa (72.5 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 19% more; tensile strength follows at 750 MPa (109 ksi) vs 620 MPa (89.9 ksi). 18NiCrMo14-6 is the more ductile: elongation 16% versus 14% for 34MnB5, and 18NiCrMo14-6 is harder (220 HB vs 185 HB). 34MnB5 runs hotter in service (400°C vs 200°C continuous) and 34MnB5 conducts heat better (44 W/m·K vs 34 W/m·K). On the shop floor, 34MnB5 machines more easily (good vs fair), 34MnB5 welds better (good vs poor), and 34MnB5 sits in a lower cost tier (standard, $$) than 18NiCrMo14-6 (premium, $$$).

18NiCrMo14-6Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

34MnB5Choose it when the part sees heat, or when the part is machined in volume.

18NiCrMo14-6 vs 34MnB5: properties

18NiCrMo14-634MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

750 MPa109 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

500 MPa72.5 ksi
420 MPa60.9 ksi

Elongation at Break

16%
14%

Compressive Strength

760 MPa110 ksi
—

Shear Strength

460 MPa66.7 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

220 HB
185 HB

Hardness, Rockwell B

96 HRB
89 HRB

Hardness, Vickers

230 HV
195 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 45%

Physical

Density and transition temperatures.

Liquidus Temperature

1,480°C2,696 °F
1,495°C2,723 °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
470 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
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
-0.6 V

Corrosion Resistance

12 / 100
11 / 100

Manufacturability

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

Machinability

45 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

48%
60%

Weldability

25 / 100
55 / 100

Formability (cold)

45 / 100
60 / 100

Castability

30 / 100
—

Polishability

75 / 100
55 / 100

Same in both: Brazeability / Solderability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.5 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
40 L/kg4.8 gal/lb

Same in both: Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

96 kN·m/kg
79 kN·m/kg

Modulus of Resilience

595 kJ/m³
420 kJ/m³

Thermal Diffusivity

9.4 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

11
10

Same in both: Specific Stiffness (E / density) 26.8 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 scale34MnB518NiCrMo14-6

Manufacturing and finishing

Capability18NiCrMo14-634MnB5
Sheet metal—Yes
Default condition—CR
Relative cost$$$ Premium$$ Standard
Min. machined wall——
Best machined surface——
Black Oxide—Yes
Cerakote—Yes
Chrome Plating—Yes
E-Coating—Yes
Hot-Dip Galvanizing—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes
Powder Coating—Yes
Tin Plating—Yes
Zinc Plating—Yes
Zinc-Flake (Dip-Spin) Coating—Yes
Zinc-Nickel Plating—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 34MnB5 — frequently asked

Is 18NiCrMo14-6 stronger than 34MnB5?

Yes. 18NiCrMo14-6 has a typical yield strength of 500 MPa (72.5 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 19% more. Tensile strength is 750 MPa (109 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 18NiCrMo14-6 or 34MnB5?

34MnB5 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 34MnB5?

34MnB5. Its machinability rates good (55/100) against fair (45/100) for 18NiCrMo14-6; for welding the order is 34MnB5 first (good, 55/100) then 18NiCrMo14-6 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 18NiCrMo14-6 and 34MnB5 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.