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Steel 10B21 vs 20MnVB

Steel · grade comparison

Steel 10B21 and 20MnVB are both steel grades. 20MnVB 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 1,150 MPa (167 ksi) vs 430 MPa (62.4 ksi). In exchange, 10B21 is the more ductile: elongation 30% versus 12% for 20MnVB, and 20MnVB is harder (360 HB vs 126 HB). 10B21 runs hotter in service (400°C vs 200°C continuous) and 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 fair).

10B21Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

20MnVBChoose it when strength drives the design.

10B21 vs 20MnVB: properties

10B2120MnVB

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

205 GPa29.7 Msi
210 GPa30.5 Msi

Tensile Strength (Ultimate)

430 MPa62.4 ksi
1,150 MPa167 ksi

Yield Strength (0.2% offset)

290 MPa42.1 ksi
950 MPa138 ksi

Elongation at Break

30%
12%

Reduction in Area

55%
50%

Shear Strength

275 MPa39.9 ksi
690 MPa100 ksi

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
500 MPa72.5 ksi

Fracture Toughness (K_IC)

90 MPa·√m81.9 ksi·√in
55 MPa·√m50.1 ksi·√in

Charpy V-Notch Impact (RT)

65 J47.9 ft·lbf
62 J45.7 ft·lbf

Hardness, Brinell

126 HB
360 HB

Hardness, Rockwell B

71 HRB
—

Compressive Strength

—
970 MPa141 ksi

Hardness, Rockwell C

—
38 HRC

Hardness, Vickers

—
375 HV

Same in both: 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
1,425°C2,597 °F

Liquidus Temperature

1,510°C2,750 °F
1,500°C2,732 °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
11.9 µm/m·K6.6 µin/in·°F

Latent Heat of Fusion

247 J/g106 BTU/lb
270 J/g116 BTU/lb

Max Service Temperature (continuous)

400°C752 °F
200°C392 °F

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

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
-0.62 V

Corrosion Resistance

10 / 100
11 / 100

Manufacturability

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

Machinability

62 / 100
38 / 100

Machinability Rating (AISI 1212 = 100 %)

65%
40%

Weldability

85 / 100
35 / 100

Formability (cold)

82 / 100
20 / 100

Brazeability / Solderability

70 / 100
55 / 100

Polishability

45 / 100
65 / 100

Castability

—
30 / 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
2.1 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
146 kN·m/kg

Specific Stiffness (E / density)

26.1 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

205 kJ/m³
2,149 kJ/m³

Thermal Diffusivity

14.1 mm²/s
11.9 mm²/s

Thermal Shock Resistance Index

9
20

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 scale10B2120MnVB

Manufacturing and finishing

Capability10B2120MnVB
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 20MnVB — frequently asked

Is 20MnVB stronger than 10B21?

Yes. 20MnVB 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 1,150 MPa (167 ksi) vs 430 MPa (62.4 ksi).

Which is cheaper, 10B21 or 20MnVB?

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 20MnVB?

10B21. Its machinability rates good (62/100) against fair (38/100) for 20MnVB; for welding the order is 10B21 first (excellent, 85/100) then 20MnVB (fair, 35/100).

Ready to make it?

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