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Steel 15B35 vs 86B45

Steel · grade comparison

Steel 15B35 and 86B45 are both steel grades. 86B45 is the stronger of the two: yield strength 950 MPa (138 ksi) against 620 MPa (89.9 ksi) for 15B35, about 53% more; tensile strength follows at 1,080 MPa (157 ksi) vs 730 MPa (106 ksi). 86B45 is the more ductile: elongation 16% versus 13% for 15B35, and 86B45 is harder (320 HB vs 217 HB). 86B45 runs hotter in service (400°C vs 350°C continuous) and 15B35 conducts electricity better (9.5 % IACS vs 7.8 % IACS). On the shop floor, 15B35 machines more easily (good vs fair) and 15B35 welds better (fair vs poor).

15B35Choose it when the part is machined in volume, or when it will be welded.

86B45Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

15B35 vs 86B45: properties

15B3586B45

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

730 MPa106 ksi
1,080 MPa157 ksi

Yield Strength (0.2% offset)

620 MPa89.9 ksi
950 MPa138 ksi

Elongation at Break

13%
16%

Reduction in Area

40%
50%

Compressive Strength

620 MPa89.9 ksi
960 MPa139 ksi

Shear Strength

440 MPa63.8 ksi
650 MPa94.3 ksi

Fatigue Strength (Endurance Limit)

330 MPa47.9 ksi
490 MPa71.1 ksi

Charpy V-Notch Impact (RT)

25 J18.4 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

217 HB
320 HB

Hardness, Rockwell B

96 HRB
—

Fracture Toughness (K_IC)

—
80 MPa·√m72.8 ksi·√in

Hardness, Rockwell C

—
34 HRC

Hardness, Vickers

—
336 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · 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)

1,425°C2,597 °F
1,420°C2,588 °F

Liquidus Temperature

1,495°C2,723 °F
1,490°C2,714 °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

46 W/m·K26.6 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.9 µm/m·K6.6 µin/in·°F
12.3 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

247 J/g106 BTU/lb
260 J/g112 BTU/lb

Max Service Temperature (continuous)

350°C662 °F
400°C752 °F

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 475 J/kg·K0.11 BTU/lb·°F

Electrical

Conductivity and insulation.

Electrical Conductivity

9.5 % IACS
7.8 % 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).

Corrosion Resistance

10 / 100
11 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V

Manufacturability

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

Machinability

55 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
45%

Weldability

40 / 100
28 / 100

Formability (cold)

55 / 100
22 / 100

Brazeability / Solderability

60 / 100
50 / 100

Polishability

55 / 100
62 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
28 MJ/kg12,038 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.2 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
60 L/kg7.2 gal/lb

Same in both: Typical Recycled Content 30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

93 kN·m/kg
138 kN·m/kg

Modulus of Resilience

938 kJ/m³
2,201 kJ/m³

Thermal Diffusivity

12.3 mm²/s
11.3 mm²/s

Thermal Shock Resistance Index

14
18

Same in both: Specific Stiffness (E / density) 26.1 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 scale15B3586B45

Manufacturing and finishing

Capability15B3586B45
Default condition——
Relative cost$ Budget$ Budget
Min. machined wall——
Best machined surface——

Both take the same 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

15B35 vs 86B45 — frequently asked

Is 86B45 stronger than 15B35?

Yes. 86B45 has a typical yield strength of 950 MPa (138 ksi) against 620 MPa (89.9 ksi) for 15B35 — about 53% more. Tensile strength is 1,080 MPa (157 ksi) vs 730 MPa (106 ksi).

Which is cheaper, 15B35 or 86B45?

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

Which is easier to machine, 15B35 or 86B45?

15B35. Its machinability rates good (55/100) against fair (42/100) for 86B45; for welding the order is 15B35 first (fair, 40/100) then 86B45 (poor, 28/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 15B35 and 86B45 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.