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Steel 33B2 vs 34MnB5

Steel · grade comparison

Steel 33B2 and 34MnB5 are both steel grades. 33B2 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 420 MPa (60.9 ksi) for 34MnB5, about 24% more. In exchange, 34MnB5 is the more ductile: elongation 14% versus 12% for 33B2. 34MnB5 runs hotter in service (400°C vs 350°C continuous) and 33B2 conducts electricity better (9 % IACS vs 8 % IACS). On the shop floor, 34MnB5 welds better (good vs fair) and 33B2 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

33B2Choose it when strength drives the design, or when cost is the deciding factor.

34MnB5Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

33B2 vs 34MnB5: properties

33B234MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Yield Strength (0.2% offset)

520 MPa75.4 ksi
420 MPa60.9 ksi

Elongation at Break

12%
14%

Reduction in Area

55%
45%

Compressive Strength

520 MPa75.4 ksi
—

Shear Strength

380 MPa55.1 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

290 MPa42.1 ksi
280 MPa40.6 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

180 HB
185 HB

Hardness, Vickers

190 HV
195 HV

Fracture Toughness (K_IC)

—
55 MPa·√m50.1 ksi·√in

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 · Tensile Strength (Ultimate) 620 MPa89.9 ksi · Hardness, Rockwell B 89 HRB

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

12.1 µm/m·K6.7 µin/in·°F
12.5 µm/m·K6.9 µin/in·°F

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
8 % IACS

Electrical Resistivity

1.9×10⁻⁷ Ω·m7.48 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)

-0.61 V
-0.6 V

Corrosion Resistance

10 / 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 %)

70%
60%

Weldability

45 / 100
55 / 100

Formability (cold)

75 / 100
60 / 100

Brazeability / Solderability

60 / 100
45 / 100

Same in both: Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2 kg CO₂/kg

Typical Recycled Content

30%
25%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Water 40 L/kg4.8 gal/lb

Common Calculations

Ratios derived from the values above.

Modulus of Resilience

644 kJ/m³
420 kJ/m³

Thermal Diffusivity

12.5 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

11
10

Same in both: Specific Strength (UTS / density) 79 kN·m/kg · 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 scale34MnB533B2

Manufacturing and finishing

Capability33B234MnB5
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.

33B2 vs 34MnB5 — frequently asked

Is 33B2 stronger than 34MnB5?

Yes. 33B2 has a typical yield strength of 520 MPa (75.4 ksi) against 420 MPa (60.9 ksi) for 34MnB5 — about 24% more. Tensile strength is 620 MPa (89.9 ksi) vs 620 MPa (89.9 ksi).

Which is cheaper, 33B2 or 34MnB5?

33B2 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, 33B2 or 34MnB5?

33B2, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 34MnB5; for welding the order is 34MnB5 first (good, 55/100) then 33B2 (fair, 45/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 33B2 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.