FabDigitFabDigit

Steel 15NiMn6 vs 34MnB5

Steel · grade comparison

Steel 15NiMn6 and 34MnB5 are both steel grades. 34MnB5 is the stronger of the two: yield strength 420 MPa (60.9 ksi) against 380 MPa (55.1 ksi) for 15NiMn6, about 11% more; tensile strength follows at 620 MPa (89.9 ksi) vs 560 MPa (81.2 ksi). In exchange, 15NiMn6 is the more ductile: elongation 26% versus 14% for 34MnB5, and 34MnB5 is harder (185 HB vs 165 HB). 34MnB5 runs hotter in service (400°C vs 350°C continuous). On the shop floor, 15NiMn6 welds better (very good vs good).

15NiMn6Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

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

15NiMn6 vs 34MnB5: properties

15NiMn634MnB5

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Shear Modulus

81 GPa11.7 Msi
80 GPa11.6 Msi

Tensile Strength (Ultimate)

560 MPa81.2 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

380 MPa55.1 ksi
420 MPa60.9 ksi

Elongation at Break

26%
14%

Reduction in Area

55%
45%

Compressive Strength

380 MPa55.1 ksi
—

Shear Strength

360 MPa52.2 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

150 J111 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

165 HB
185 HB

Hardness, Rockwell B

85 HRB
89 HRB

Hardness, Vickers

173 HV
195 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,500°C2,732 °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

41 W/m·K23.7 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

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-80°C-112 °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

7.5 % IACS
8 % IACS

Electrical Resistivity

2.3×10⁻⁷ Ω·m9.06 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

12 / 100
11 / 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.

Weldability

75 / 100
55 / 100

Formability (cold)

65 / 100
60 / 100

Brazeability / Solderability

50 / 100
45 / 100

Polishability

60 / 100
55 / 100

Same in both: Machinability 55 / 100 · Machinability Rating (AISI 1212 = 100 %) 60%

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

34 MJ/kg14,617 BTU/lb
25 MJ/kg10,748 BTU/lb

Embodied Carbon (primary production)

2.5 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%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

71 kN·m/kg
79 kN·m/kg

Modulus of Resilience

344 kJ/m³
420 kJ/m³

Thermal Diffusivity

11.1 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

9
10

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 scale34MnB515NiMn6

Manufacturing and finishing

Capability15NiMn634MnB5
Sheet metal—Yes
Default condition—CR
Relative cost$$ Standard$$ 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.

15NiMn6 vs 34MnB5 — frequently asked

Is 34MnB5 stronger than 15NiMn6?

Yes. 34MnB5 has a typical yield strength of 420 MPa (60.9 ksi) against 380 MPa (55.1 ksi) for 15NiMn6 — about 11% more. Tensile strength is 620 MPa (89.9 ksi) vs 560 MPa (81.2 ksi).

Which is cheaper, 15NiMn6 or 34MnB5?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which welds better, 15NiMn6 or 34MnB5?

15NiMn6. Its weldability rates very good (75/100) against good (55/100) for 34MnB5.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 15NiMn6 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.