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Steel 34MnB5 vs P355QL2

Steel · grade comparison

Steel 34MnB5 and P355QL2 are both steel grades. 34MnB5 is the stronger of the two: tensile strength 620 MPa (89.9 ksi) against 550 MPa (79.8 ksi) for P355QL2, about 13% more. In exchange, P355QL2 is the more ductile: elongation 26% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 165 HB). On the shop floor, P355QL2 welds better (very good vs good) and P355QL2 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

34MnB5Choose it when strength drives the design.

P355QL2Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

34MnB5 vs P355QL2: properties

34MnB5P355QL2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

80 GPa11.6 Msi
81 GPa11.7 Msi

Poisson's Ratio

0.29
0.3

Tensile Strength (Ultimate)

620 MPa89.9 ksi
550 MPa79.8 ksi

Elongation at Break

14%
26%

Reduction in Area

45%
60%

Shear Strength

400 MPa58 ksi
340 MPa49.3 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
150 MPa·√m137 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
180 J133 ft·lbf

Hardness, Brinell

185 HB
165 HB

Hardness, Rockwell B

89 HRB
85 HRB

Hardness, Vickers

195 HV
175 HV

Compressive Strength

—
420 MPa60.9 ksi

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Yield Strength (0.2% offset) 420 MPa60.9 ksi

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,420°C2,588 °F
1,460°C2,660 °F

Liquidus Temperature

1,495°C2,723 °F
1,510°C2,750 °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)

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

Latent Heat of Fusion

250 J/g107 BTU/lb
270 J/g116 BTU/lb

Min Service Temperature

-40°C-40 °F
-60°C-76 °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 · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
7.8 % IACS

Same in both: 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)

-0.6 V
-0.62 V

Corrosion Resistance

11 / 100
12 / 100

Manufacturability

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

Machinability

55 / 100
58 / 100

Weldability

55 / 100
82 / 100

Formability (cold)

60 / 100
65 / 100

Brazeability / Solderability

45 / 100
55 / 100

Polishability

55 / 100
50 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 60%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
27 MJ/kg11,608 BTU/lb

Embodied Carbon (primary production)

2 kg CO₂/kg
2.1 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
45 L/kg5.4 gal/lb

Typical Recycled Content

25%
20%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
70 kN·m/kg

Same in both: Specific Stiffness (E / density) 26.8 MN·m/kg · Modulus of Resilience 420 kJ/m³ · Thermal Diffusivity 11.9 mm²/s · Thermal Shock Resistance Index 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 scale34MnB5P355QL2

Manufacturing and finishing

Capability34MnB5P355QL2
Sheet metalYes—
Default conditionCR—
Relative cost$$ Standard$ Budget
Min. machined wall——
Best machined surface——
Black OxideYes—
CerakoteYes—
Chrome PlatingYes—
E-CoatingYes—
Hot-Dip GalvanizingYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—
Tin PlatingYes—
Zinc PlatingYes—
Zinc-Flake (Dip-Spin) CoatingYes—
Zinc-Nickel PlatingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

34MnB5 vs P355QL2 — frequently asked

Is 34MnB5 stronger than P355QL2?

Yes. 34MnB5 has a typical tensile strength of 620 MPa (89.9 ksi) against 550 MPa (79.8 ksi) for P355QL2 — about 13% more.

Which is cheaper, 34MnB5 or P355QL2?

P355QL2 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 welds better, 34MnB5 or P355QL2?

P355QL2. Its weldability rates very good (82/100) against good (55/100) for 34MnB5.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5 and P355QL2 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.