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Steel 17B2 vs 34MnB5

Steel · grade comparison

Steel 17B2 and 34MnB5 are both steel grades. 34MnB5 is the stronger of the two: tensile strength 620 MPa (89.9 ksi) against 520 MPa (75.4 ksi) for 17B2, about 19% more. 34MnB5 is harder — 185 HB against 150 HB for 17B2 — which matters for wear surfaces and threads. 34MnB5 runs hotter in service (400°C vs 300°C continuous) and 17B2 conducts electricity better (9.5 % IACS vs 8 % IACS). On the shop floor, 17B2 welds better (very good vs good), 17B2 forms better (very good vs good), and 17B2 sits in a lower cost tier (budget, $) than 34MnB5 (standard, $$).

17B2Choose it when it will be welded, or when cost is the deciding factor.

34MnB5Choose it when strength drives the design, or when surface hardness matters.

17B2 vs 34MnB5: properties

17B234MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

207 GPa30 Msi
210 GPa30.5 Msi

Tensile Strength (Ultimate)

520 MPa75.4 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

400 MPa58 ksi
420 MPa60.9 ksi

Elongation at Break

13%
14%

Reduction in Area

55%
45%

Shear Strength

330 MPa47.9 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
280 MPa40.6 ksi

Charpy V-Notch Impact (RT)

45 J33.2 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

150 HB
185 HB

Hardness, Rockwell B

80 HRB
89 HRB

Hardness, Vickers

158 HV
195 HV

Fracture Toughness (K_IC)

—
55 MPa·√m50.1 ksi·√in

Same in both: Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,495°C2,723 °F
1,420°C2,588 °F

Liquidus Temperature

1,520°C2,768 °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 Conductivity

47 W/m·K27.2 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

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

Max Service Temperature (continuous)

300°C572 °F
400°C752 °F

Min Service Temperature

-20°C-4 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.5 % IACS
8 % IACS

Electrical Resistivity

1.8×10⁻⁷ Ω·m7.09 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

58 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

68%
60%

Weldability

70 / 100
55 / 100

Formability (cold)

78 / 100
60 / 100

Brazeability / Solderability

70 / 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

Embodied Water

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

Typical Recycled Content

30%
25%

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)

66 kN·m/kg
79 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

386 kJ/m³
420 kJ/m³

Thermal Diffusivity

12.7 mm²/s
11.9 mm²/s

Same in both: 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 scale34MnB517B2

Manufacturing and finishing

Capability17B234MnB5
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.

17B2 vs 34MnB5 — frequently asked

Is 34MnB5 stronger than 17B2?

Yes. 34MnB5 has a typical tensile strength of 620 MPa (89.9 ksi) against 520 MPa (75.4 ksi) for 17B2 — about 19% more.

Which is cheaper, 17B2 or 34MnB5?

17B2 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, 17B2 or 34MnB5?

17B2. Its weldability rates very good (70/100) against good (55/100) for 34MnB5.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 17B2 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.