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Steel 10B21 vs 86B45

Steel · grade comparison

Steel 10B21 and 86B45 are both steel grades. 86B45 is the stronger of the two: yield strength 950 MPa (138 ksi) against 290 MPa (42.1 ksi) for 10B21, about 3.3 times as much; tensile strength follows at 1,080 MPa (157 ksi) vs 430 MPa (62.4 ksi). In exchange, 10B21 is the more ductile: elongation 30% versus 16% for 86B45, and 86B45 is harder (320 HB vs 126 HB). 10B21 conducts heat better (51.9 W/m·K vs 42 W/m·K). On the shop floor, 10B21 machines more easily (good vs fair) and 10B21 welds better (excellent vs poor).

10B21Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

86B45Choose it when strength drives the design.

10B21 vs 86B45: properties

10B2186B45

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

430 MPa62.4 ksi
1,080 MPa157 ksi

Yield Strength (0.2% offset)

290 MPa42.1 ksi
950 MPa138 ksi

Elongation at Break

30%
16%

Reduction in Area

55%
50%

Shear Strength

275 MPa39.9 ksi
650 MPa94.3 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
490 MPa71.1 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
80 MPa·√m72.8 ksi·√in

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

126 HB
320 HB

Hardness, Rockwell B

71 HRB
—

Compressive Strength

—
960 MPa139 ksi

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)

1,465°C2,669 °F
1,420°C2,588 °F

Liquidus Temperature

1,510°C2,750 °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

51.9 W/m·K30 BTU/hr·ft·°F
42 W/m·K24.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 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

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
7.8 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 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

62 / 100
42 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
45%

Weldability

85 / 100
28 / 100

Formability (cold)

82 / 100
22 / 100

Brazeability / Solderability

70 / 100
50 / 100

Polishability

45 / 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)

55 kN·m/kg
138 kN·m/kg

Modulus of Resilience

205 kJ/m³
2,201 kJ/m³

Thermal Diffusivity

14.1 mm²/s
11.3 mm²/s

Thermal Shock Resistance Index

9
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 scale10B2186B45

Manufacturing and finishing

Capability10B2186B45
CNC machiningYes—
Sheet metalYes—
Default conditionHR—
Relative cost$ Budget$ Budget
Min. machined wall0.8 mm—
Best machined surfaceRa 1.6 µm—
AlCrNYes—
AlTiNYes—
Black OxideYes—
CVD Al2O3Yes—
CVD TiCNYes—
CVD TiNYes—
CerakoteYes—
Chrome PlatingYes—
CrNYes—
DLCYes—
E-CoatingYes—
HVOF CoatingYes—
Hot-Dip GalvanizingYes—
MoS2Yes—
Multilayer CVDYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—

They share 9 finishes: Copper Plating, Electroless Nickel (EN), Epoxy Coating, Gold Plating, Hard Chrome Plating, Manganese Phosphate, Plasma Spray, Silver Plating, Zinc Phosphate.

10B21 vs 86B45 — frequently asked

Is 86B45 stronger than 10B21?

Yes. 86B45 has a typical yield strength of 950 MPa (138 ksi) against 290 MPa (42.1 ksi) for 10B21 — about 3.3 times as much. Tensile strength is 1,080 MPa (157 ksi) vs 430 MPa (62.4 ksi).

Which is cheaper, 10B21 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, 10B21 or 86B45?

10B21. Its machinability rates good (62/100) against fair (42/100) for 86B45; for welding the order is 10B21 first (excellent, 85/100) then 86B45 (poor, 28/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 10B21 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.