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Steel 34MnB5 vs S355ML

Steel · grade comparison

Steel 34MnB5 and S355ML are both steel grades. 34MnB5 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 390 MPa (56.6 ksi) for S355ML, about 8% more; tensile strength follows at 620 MPa (89.9 ksi) vs 520 MPa (75.4 ksi). In exchange, S355ML is the more ductile: elongation 26% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 162 HB). S355ML conducts electricity better (10 % IACS vs 8 % IACS). On the shop floor, S355ML welds better (excellent vs good) and S355ML sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

34MnB5Choose it when strength drives the design.

S355MLChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

34MnB5 vs S355ML: properties

34MnB5S355ML

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
520 MPa75.4 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
390 MPa56.6 ksi

Elongation at Break

14%
26%

Reduction in Area

45%
60%

Shear Strength

400 MPa58 ksi
320 MPa46.4 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
255 MPa37 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
200 J148 ft·lbf

Hardness, Brinell

185 HB
162 HB

Hardness, Rockwell B

89 HRB
85 HRB

Hardness, Vickers

195 HV
172 HV

Compressive Strength

—
380 MPa55.1 ksi

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi

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
1,520°C2,768 °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 Conductivity

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

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

400°C752 °F
380°C716 °F

Min Service Temperature

-40°C-40 °F
-50°C-58 °F

Same in both: Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
10 % IACS

Electrical Resistivity

2.2×10⁻⁷ Ω·m8.66 µΩ·in
1.7×10⁻⁷ Ω·m6.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.6 V
-0.65 V

Corrosion Resistance

11 / 100
12 / 100

Manufacturability

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

Machinability

55 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
65%

Weldability

55 / 100
95 / 100

Formability (cold)

60 / 100
78 / 100

Brazeability / Solderability

45 / 100
55 / 100

Polishability

55 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2 kg CO₂/kg · Embodied Water 40 L/kg4.8 gal/lb · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
66 kN·m/kg

Modulus of Resilience

420 kJ/m³
362 kJ/m³

Thermal Diffusivity

11.9 mm²/s
12.5 mm²/s

Thermal Shock Resistance Index

10
9

Same in both: 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 scale34MnB5S355ML

Manufacturing and finishing

Capability34MnB5S355ML
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 S355ML — frequently asked

Is 34MnB5 stronger than S355ML?

Yes. 34MnB5 has a typical yield strength of 420 MPa (60.9 ksi) against 390 MPa (56.6 ksi) for S355ML — about 8% more. Tensile strength is 620 MPa (89.9 ksi) vs 520 MPa (75.4 ksi).

Which is cheaper, 34MnB5 or S355ML?

S355ML 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, 34MnB5 or S355ML?

S355ML, by a small margin. Both rate good for machinability — 60/100 against 55/100 for 34MnB5; for welding the order is S355ML first (excellent, 95/100) then 34MnB5 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5 and S355ML 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.