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Steel 10B21 vs 20B46

Steel · grade comparison

Steel 10B21 and 20B46 are both steel grades. 20B46 is the stronger of the two: yield strength 880 MPa (128 ksi) against 290 MPa (42.1 ksi) for 10B21, about 3.0 times as much; tensile strength follows at 1,030 MPa (149 ksi) vs 430 MPa (62.4 ksi). In exchange, 10B21 is the more ductile: elongation 30% versus 16% for 20B46, and 20B46 is harder (311 HB vs 126 HB). 10B21 conducts heat better (51.9 W/m·K vs 44 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.

20B46Choose it when strength drives the design.

10B21 vs 20B46: properties

10B2120B46

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

430 MPa62.4 ksi
1,030 MPa149 ksi

Yield Strength (0.2% offset)

290 MPa42.1 ksi
880 MPa128 ksi

Elongation at Break

30%
16%

Reduction in Area

55%
52%

Shear Strength

275 MPa39.9 ksi
620 MPa89.9 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
465 MPa67.4 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
70 MPa·√m63.7 ksi·√in

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

126 HB
311 HB

Hardness, Rockwell B

71 HRB
—

Compressive Strength

—
890 MPa129 ksi

Hardness, Rockwell C

—
32 HRC

Hardness, Vickers

—
327 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
44 W/m·K25.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

11.7 µm/m·K6.5 µin/in·°F
12.2 µm/m·K6.8 µin/in·°F

Latent Heat of Fusion

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

Min Service Temperature

-30°C-22 °F
-40°C-40 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Max Service Temperature (continuous) 400°C752 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

10.8 % IACS
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).

Galvanic Potential (seawater, vs SCE)

-0.61 V
-0.65 V

Corrosion Resistance

10 / 100
12 / 100

Manufacturability

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

Machinability

62 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
45%

Weldability

85 / 100
30 / 100

Formability (cold)

82 / 100
30 / 100

Brazeability / Solderability

70 / 100
45 / 100

Polishability

45 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

25 MJ/kg10,748 BTU/lb
30 MJ/kg12,898 BTU/lb

Embodied Carbon (primary production)

1.9 kg CO₂/kg
2.3 kg CO₂/kg

Embodied Water

40 L/kg4.8 gal/lb
55 L/kg6.6 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
131 kN·m/kg

Modulus of Resilience

205 kJ/m³
1,889 kJ/m³

Thermal Diffusivity

14.1 mm²/s
11.9 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 scale10B2120B46

Manufacturing and finishing

Capability10B2120B46
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 20B46 — frequently asked

Is 20B46 stronger than 10B21?

Yes. 20B46 has a typical yield strength of 880 MPa (128 ksi) against 290 MPa (42.1 ksi) for 10B21 — about 3.0 times as much. Tensile strength is 1,030 MPa (149 ksi) vs 430 MPa (62.4 ksi).

Which is cheaper, 10B21 or 20B46?

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 20B46?

10B21. Its machinability rates good (62/100) against fair (45/100) for 20B46; for welding the order is 10B21 first (excellent, 85/100) then 20B46 (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 10B21 and 20B46 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.