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Steel 20MnNb6 vs A285

Steel · grade comparison

Steel 20MnNb6 and A285 are both steel grades. 20MnNb6 is the stronger of the two: yield strength 385 MPa (55.8 ksi) against 250 MPa (36.3 ksi) for A285, about 54% more; tensile strength follows at 540 MPa (78.3 ksi) vs 450 MPa (65.3 ksi). In exchange, A285 is the more ductile: elongation 30% versus 25% for 20MnNb6, and 20MnNb6 is harder (155 HB vs 130 HB). On the shop floor, 20MnNb6 sits in a lower cost tier (budget, $) than A285 (standard, $$).

20MnNb6Choose it when strength drives the design, or when cost is the deciding factor.

A285Choose it when the part is bent, formed or impact-loaded.

20MnNb6 vs A285: properties

20MnNb6A285

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

210 GPa30.5 Msi
200 GPa29 Msi

Shear Modulus

81 GPa11.7 Msi
79 GPa11.5 Msi

Tensile Strength (Ultimate)

540 MPa78.3 ksi
450 MPa65.3 ksi

Yield Strength (0.2% offset)

385 MPa55.8 ksi
250 MPa36.3 ksi

Elongation at Break

25%
30%

Reduction in Area

60%
55%

Compressive Strength

385 MPa55.8 ksi
250 MPa36.3 ksi

Shear Strength

330 MPa47.9 ksi
290 MPa42.1 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
200 MPa29 ksi

Fracture Toughness (K_IC)

130 MPa·√m118 ksi·√in
100 MPa·√m91 ksi·√in

Charpy V-Notch Impact (RT)

100 J73.8 ft·lbf
40 J29.5 ft·lbf

Hardness, Brinell

155 HB
130 HB

Hardness, Rockwell B

82 HRB
72 HRB

Hardness, Vickers

163 HV
—

Same in both: Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Melting Point (Solidus)

1,490°C2,714 °F
1,460°C2,660 °F

Liquidus Temperature

1,520°C2,768 °F
1,515°C2,759 °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

48 W/m·K27.7 BTU/hr·ft·°F
51 W/m·K29.5 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
425°C797 °F

Min Service Temperature

-20°C-4 °F
-29°C-20 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12 µm/m·K6.7 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

10 % IACS
10.8 % IACS

Electrical Resistivity

1.7×10⁻⁷ Ω·m6.69 µΩ·in
1.6×10⁻⁷ Ω·m6.3 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

11 / 100
10 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V

Manufacturability

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

Machinability

60 / 100
68 / 100

Weldability

88 / 100
92 / 100

Formability (cold)

70 / 100
82 / 100

Castability

40 / 100
—

Polishability

45 / 100
40 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 65% · Brazeability / Solderability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

2.1 kg CO₂/kg
1.9 kg CO₂/kg

Embodied Water

50 L/kg6 gal/lb
30 L/kg3.6 gal/lb

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Typical Recycled Content 25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

69 kN·m/kg
57 kN·m/kg

Specific Stiffness (E / density)

26.8 MN·m/kg
25.5 MN·m/kg

Modulus of Resilience

353 kJ/m³
156 kJ/m³

Thermal Diffusivity

13 mm²/s
13.8 mm²/s

Same in both: Thermal Shock Resistance Index 10

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 scaleA28520MnNb6

Manufacturing and finishing

Capability20MnNb6A285
CNC machining—Yes
Sheet metal—Yes
Default condition—HR
Relative cost$ Budget$$ Standard
Min. machined wall—0.8 mm
Best machined surface—Ra 1.6 µm
AlCrN—Yes
AlTiN—Yes
Black Oxide—Yes
CVD Al2O3—Yes
CVD TiCN—Yes
CVD TiN—Yes
Cerakote—Yes
Chrome Plating—Yes
CrN—Yes
DLC—Yes
E-Coating—Yes
HVOF Coating—Yes
Hot-Dip Galvanizing—Yes
MoS2—Yes
Multilayer CVD—Yes
Nickel Plating—Yes
PTFE Coating—Yes
Painting—Yes

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

20MnNb6 vs A285 — frequently asked

Is 20MnNb6 stronger than A285?

Yes. 20MnNb6 has a typical yield strength of 385 MPa (55.8 ksi) against 250 MPa (36.3 ksi) for A285 — about 54% more. Tensile strength is 540 MPa (78.3 ksi) vs 450 MPa (65.3 ksi).

Which is cheaper, 20MnNb6 or A285?

20MnNb6 is the lower-cost material: it sits in the budget tier ($) while A285 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 20MnNb6 or A285?

A285, by a small margin. Both rate good for machinability — 68/100 against 60/100 for 20MnNb6.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20MnNb6 and A285 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.