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Steel 34MnB5 vs S235J2W

Steel · grade comparison

Steel 34MnB5 and S235J2W are both steel grades. 34MnB5 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 265 MPa (38.4 ksi) for S235J2W, about 58% more; tensile strength follows at 620 MPa (89.9 ksi) vs 420 MPa (60.9 ksi). In exchange, S235J2W is the more ductile: elongation 30% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 125 HB). 34MnB5 runs hotter in service (400°C vs 350°C continuous). On the shop floor, S235J2W welds better (excellent vs good) and S235J2W sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

34MnB5Choose it when strength drives the design, or when the part sees heat.

S235J2WChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

34MnB5 vs S235J2W: properties

34MnB5S235J2W

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
420 MPa60.9 ksi

Yield Strength (0.2% offset)

420 MPa60.9 ksi
265 MPa38.4 ksi

Elongation at Break

14%
30%

Reduction in Area

45%
55%

Shear Strength

400 MPa58 ksi
270 MPa39.2 ksi

Fatigue Strength (Endurance Limit)

280 MPa40.6 ksi
180 MPa26.1 ksi

Fracture Toughness (K_IC)

55 MPa·√m50.1 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
60 J44.3 ft·lbf

Hardness, Brinell

185 HB
125 HB

Hardness, Rockwell B

89 HRB
70 HRB

Hardness, Vickers

195 HV
132 HV

Compressive Strength

—
250 MPa36.3 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
1,470°C2,678 °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
48 W/m·K27.7 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

Latent Heat of Fusion

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

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Min Service Temperature

-40°C-40 °F
-20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

8 % IACS
8.6 % IACS

Electrical Resistivity

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

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

11 / 100
30 / 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

55 / 100
62 / 100

Weldability

55 / 100
88 / 100

Formability (cold)

60 / 100
80 / 100

Brazeability / Solderability

45 / 100
60 / 100

Polishability

55 / 100
45 / 100

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

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2 kg CO₂/kg
1.9 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

25%
30%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

79 kN·m/kg
54 kN·m/kg

Modulus of Resilience

420 kJ/m³
167 kJ/m³

Thermal Diffusivity

11.9 mm²/s
13.3 mm²/s

Thermal Shock Resistance Index

10
8

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 scale34MnB5S235J2W

Manufacturing and finishing

Capability34MnB5S235J2W
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 S235J2W — frequently asked

Is 34MnB5 stronger than S235J2W?

Yes. 34MnB5 has a typical yield strength of 420 MPa (60.9 ksi) against 265 MPa (38.4 ksi) for S235J2W — about 58% more. Tensile strength is 620 MPa (89.9 ksi) vs 420 MPa (60.9 ksi).

Which is cheaper, 34MnB5 or S235J2W?

S235J2W 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 S235J2W?

S235J2W, by a small margin. Both rate good for machinability — 62/100 against 55/100 for 34MnB5; for welding the order is S235J2W first (excellent, 88/100) then 34MnB5 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 34MnB5 and S235J2W 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.