FabDigitFabDigit

Steel 20NiCrMoS2-2 vs 34MnB5

Steel · grade comparison

Steel 20NiCrMoS2-2 and 34MnB5 are both steel grades. 34MnB5 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 330 MPa (47.9 ksi) for 20NiCrMoS2-2, about 27% more; tensile strength follows at 620 MPa (89.9 ksi) vs 510 MPa (74 ksi). In exchange, 20NiCrMoS2-2 is the more ductile: elongation 24% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 160 HB). On the shop floor, 20NiCrMoS2-2 machines more easily (66 vs 55 out of 100), 34MnB5 welds better (good vs fair), and 20NiCrMoS2-2 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

20NiCrMoS2-2Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

34MnB5Choose it when strength drives the design, or when it will be welded.

20NiCrMoS2-2 vs 34MnB5: properties

20NiCrMoS2-234MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

208 GPa30.2 Msi
210 GPa30.5 Msi

Tensile Strength (Ultimate)

510 MPa74 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

330 MPa47.9 ksi
420 MPa60.9 ksi

Elongation at Break

24%
14%

Reduction in Area

55%
45%

Compressive Strength

330 MPa47.9 ksi
—

Shear Strength

330 MPa47.9 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 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)

70 J51.6 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

160 HB
185 HB

Hardness, Rockwell B

84 HRB
89 HRB

Hardness, Vickers

168 HV
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.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,490°C2,714 °F
1,495°C2,723 °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 Expansion (CTE, 20–100 °C)

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

Same in both: Thermal Conductivity 44 W/m·K25.4 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.5 % IACS
8 % IACS

Electrical Resistivity

2.1×10⁻⁷ Ω·m8.27 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
11 / 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

66 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

80%
60%

Weldability

45 / 100
55 / 100

Formability (cold)

70 / 100
60 / 100

Brazeability / Solderability

60 / 100
45 / 100

Polishability

40 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.1 kg CO₂/kg
2 kg CO₂/kg

Embodied Water

55 L/kg6.6 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)

65 kN·m/kg
79 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

262 kJ/m³
420 kJ/m³

Thermal Shock Resistance Index

9
10

Same in both: Thermal Diffusivity 11.9 mm²/s

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 scale34MnB520NiCrMoS2-2

Manufacturing and finishing

Capability20NiCrMoS2-234MnB5
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.

20NiCrMoS2-2 vs 34MnB5 — frequently asked

Is 34MnB5 stronger than 20NiCrMoS2-2?

Yes. 34MnB5 has a typical yield strength of 420 MPa (60.9 ksi) against 330 MPa (47.9 ksi) for 20NiCrMoS2-2 — about 27% more. Tensile strength is 620 MPa (89.9 ksi) vs 510 MPa (74 ksi).

Which is cheaper, 20NiCrMoS2-2 or 34MnB5?

20NiCrMoS2-2 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, 20NiCrMoS2-2 or 34MnB5?

20NiCrMoS2-2, by a small margin. Both rate good for machinability — 66/100 against 55/100 for 34MnB5; for welding the order is 34MnB5 first (good, 55/100) then 20NiCrMoS2-2 (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20NiCrMoS2-2 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.