FabDigitFabDigit

Steel 20NiCrMo2-2 vs 34MnB5

Steel · grade comparison

Steel 20NiCrMo2-2 and 34MnB5 are both steel grades. 34MnB5 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 355 MPa (51.5 ksi) for 20NiCrMo2-2, about 18% more; tensile strength follows at 620 MPa (89.9 ksi) vs 580 MPa (84.1 ksi). In exchange, 20NiCrMo2-2 is the more ductile: elongation 20% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 165 HB). 34MnB5 runs hotter in service (400°C vs 350°C continuous). On the shop floor, 20NiCrMo2-2 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

20NiCrMo2-2Choose it when the part is bent, formed or impact-loaded, or when cost is the deciding factor.

34MnB5Choose it when strength drives the design, or when the part sees heat.

20NiCrMo2-2 vs 34MnB5: properties

20NiCrMo2-234MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
210 GPa30.5 Msi

Tensile Strength (Ultimate)

580 MPa84.1 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

355 MPa51.5 ksi
420 MPa60.9 ksi

Elongation at Break

20%
14%

Reduction in Area

50%
45%

Shear Strength

380 MPa55.1 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

275 MPa39.9 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

95 MPa·√m86.5 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

165 HB
185 HB

Hardness, Rockwell B

85 HRB
89 HRB

Hardness, Vickers

—
195 HV

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Liquidus Temperature

1,490°C2,714 °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.

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.6 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)

350°C662 °F
400°C752 °F

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 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
-0.6 V

Corrosion Resistance

12 / 100
11 / 100

Manufacturability

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

Machinability

62 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
60%

Formability (cold)

55 / 100
60 / 100

Brazeability / Solderability

60 / 100
45 / 100

Polishability

60 / 100
55 / 100

Same in both: Weldability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

31 MJ/kg13,328 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

30%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

74 kN·m/kg
79 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

304 kJ/m³
420 kJ/m³

Thermal Diffusivity

11.8 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

11
10

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 scale34MnB520NiCrMo2-2

Manufacturing and finishing

Capability20NiCrMo2-234MnB5
Sheet metal—Yes
Default condition—CR
Relative cost$ Budget$$ 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.

20NiCrMo2-2 vs 34MnB5 — frequently asked

Is 34MnB5 stronger than 20NiCrMo2-2?

Yes. 34MnB5 has a typical yield strength of 420 MPa (60.9 ksi) against 355 MPa (51.5 ksi) for 20NiCrMo2-2 — about 18% more. Tensile strength is 620 MPa (89.9 ksi) vs 580 MPa (84.1 ksi).

Which is cheaper, 20NiCrMo2-2 or 34MnB5?

20NiCrMo2-2 is the lower-cost material: it sits in the budget tier ($) while 34MnB5 is standard ($$). 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, 20NiCrMo2-2 or 34MnB5?

20NiCrMo2-2, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 34MnB5.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20NiCrMo2-2 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.