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Steel 10B21 vs 15B62

Steel · grade comparison

Steel 10B21 and 15B62 are both steel grades. 15B62 is the stronger of the two: yield strength 520 MPa (75.4 ksi) against 290 MPa (42.1 ksi) for 10B21, about 79% more; tensile strength follows at 930 MPa (135 ksi) vs 430 MPa (62.4 ksi). In exchange, 10B21 is the more ductile: elongation 30% versus 12% for 15B62, and 15B62 is harder (270 HB vs 126 HB). 10B21 runs hotter in service (400°C vs 250°C continuous) and 10B21 conducts heat better (51.9 W/m·K vs 45 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 sees heat.

15B62Choose it when strength drives the design.

10B21 vs 15B62: properties

10B2115B62

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

430 MPa62.4 ksi
930 MPa135 ksi

Yield Strength (0.2% offset)

290 MPa42.1 ksi
520 MPa75.4 ksi

Elongation at Break

30%
12%

Reduction in Area

55%
30%

Shear Strength

275 MPa39.9 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
400 MPa58 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
60 MPa·√m54.6 ksi·√in

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
15 J11.1 ft·lbf

Hardness, Brinell

126 HB
270 HB

Hardness, Rockwell B

71 HRB
100 HRB

Hardness, Vickers

—
285 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
1,480°C2,696 °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
45 W/m·K26 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 µin/in·°F
11.5 µm/m·K6.4 µin/in·°F

Latent Heat of Fusion

247 J/g106 BTU/lb
250 J/g107 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
250°C482 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
8 % IACS

Electrical Resistivity

1.6×10⁻⁷ Ω·m6.3 µΩ·in
2.1×10⁻⁷ Ω·m8.27 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 10 / 100

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%
55%

Weldability

85 / 100
20 / 100

Formability (cold)

82 / 100
30 / 100

Brazeability / Solderability

70 / 100
40 / 100

Polishability

45 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

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

Typical Recycled Content

30%
35%

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 1.9 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

55 kN·m/kg
118 kN·m/kg

Modulus of Resilience

205 kJ/m³
660 kJ/m³

Thermal Diffusivity

14.1 mm²/s
12.2 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 scale10B2115B62

Manufacturing and finishing

Capability10B2115B62
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 15B62 — frequently asked

Is 15B62 stronger than 10B21?

Yes. 15B62 has a typical yield strength of 520 MPa (75.4 ksi) against 290 MPa (42.1 ksi) for 10B21 — about 79% more. Tensile strength is 930 MPa (135 ksi) vs 430 MPa (62.4 ksi).

Which is cheaper, 10B21 or 15B62?

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 15B62?

10B21. Its machinability rates good (62/100) against fair (42/100) for 15B62; for welding the order is 10B21 first (excellent, 85/100) then 15B62 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 10B21 and 15B62 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.