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Steel 23MnB3 vs 34MnB5

Steel · grade comparison

Steel 23MnB3 and 34MnB5 are both steel grades. 23MnB3 is the stronger of the two: yield strength 920 MPa (133 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 119% more; tensile strength follows at 1,050 MPa (152 ksi) vs 620 MPa (89.9 ksi). 23MnB3 is harder — 320 HB against 185 HB for 34MnB5 — which matters for wear surfaces and threads. 34MnB5 runs hotter in service (400°C vs 350°C continuous). On the shop floor, 34MnB5 machines more easily (good vs fair), 34MnB5 welds better (good vs fair), and 34MnB5 forms better (good vs poor).

23MnB3Choose it when strength drives the design, or when surface hardness matters.

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

23MnB3 vs 34MnB5: properties

23MnB334MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,050 MPa152 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

920 MPa133 ksi
420 MPa60.9 ksi

Elongation at Break

13%
14%

Reduction in Area

52%
45%

Compressive Strength

950 MPa138 ksi
—

Shear Strength

640 MPa92.8 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

480 MPa69.6 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

70 MPa·√m63.7 ksi·√in
55 MPa·√m50.1 ksi·√in

Hardness, Brinell

320 HB
185 HB

Hardness, Rockwell C

34 HRC
—

Hardness, Vickers

335 HV
195 HV

Hardness, Rockwell B

—
89 HRB

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 · Charpy V-Notch Impact (RT) 40 J29.5 ft·lbf

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,500°C2,732 °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)

12.2 µm/m·K6.8 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °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 · Min Service Temperature -40°C-40 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8.6 % IACS
8 % IACS

Electrical Resistivity

2×10⁻⁷ Ω·m7.87 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

10 / 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

42 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

45%
60%

Weldability

40 / 100
55 / 100

Formability (cold)

30 / 100
60 / 100

Brazeability / Solderability

55 / 100
45 / 100

Polishability

60 / 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)

2.2 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)

134 kN·m/kg
79 kN·m/kg

Modulus of Resilience

2,015 kJ/m³
420 kJ/m³

Thermal Shock Resistance Index

18
10

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg · 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 scale34MnB523MnB3

Manufacturing and finishing

Capability23MnB334MnB5
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.

23MnB3 vs 34MnB5 — frequently asked

Is 23MnB3 stronger than 34MnB5?

Yes. 23MnB3 has a typical yield strength of 920 MPa (133 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 119% more. Tensile strength is 1,050 MPa (152 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 23MnB3 or 34MnB5?

23MnB3 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, 23MnB3 or 34MnB5?

34MnB5. Its machinability rates good (55/100) against fair (42/100) for 23MnB3; for welding the order is 34MnB5 first (good, 55/100) then 23MnB3 (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 23MnB3 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.