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Steel 20MnNb6 +A vs 20MnNb6 +N

Steel · 20MnNb6 temper comparison

20MnNb6 +A and 20MnNb6 +N are two conditions of the same steel grade, 20MnNb6: +A (annealed) versus +N (normalized). The chemistry is identical, so every difference below comes from the condition. 20MnNb6 +N is the stronger of the two: yield strength 385 MPa (55.8 ksi) against 300 MPa (43.5 ksi) for 20MnNb6 +A, about 28% more; tensile strength follows at 540 MPa (78.3 ksi) vs 470 MPa (68.2 ksi). In exchange, 20MnNb6 +A is the more ductile: elongation 30% versus 25% for 20MnNb6 +N, and 20MnNb6 +N is harder (155 HB vs 135 HB).

20MnNb6 +AChoose it when the part is bent, formed or impact-loaded.

20MnNb6 +NChoose it when strength drives the design.

20MnNb6 +A vs 20MnNb6 +N: properties

20MnNb6 +A20MnNb6 +N

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

470 MPa68.2 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

300 MPa43.5 ksi
385 MPa55.8 ksi

Elongation at Break

30%
25%

Reduction in Area

66%
60%

Compressive Strength

300 MPa43.5 ksi
385 MPa55.8 ksi

Shear Strength

285 MPa41.3 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

215 MPa31.2 ksi
250 MPa36.3 ksi

Fracture Toughness (K_IC)

145 MPa·√m132 ksi·√in
130 MPa·√m118 ksi·√in

Charpy V-Notch Impact (RT)

90 J66.4 ft·lbf
100 J73.8 ft·lbf

Hardness, Brinell

135 HB
155 HB

Hardness, Rockwell B

75 HRB
82 HRB

Hardness, Vickers

142 HV
163 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29

Physical

Density and transition temperatures.

Same in both: Density 7.85 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,490°C2,714 °F · Liquidus Temperature 1,520°C2,768 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

49 W/m·K28.3 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°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 · Max Service Temperature (continuous) 400°C752 °F · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 10 % IACS · Electrical Resistivity 1.7×10⁻⁷ Ω·m6.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 11 / 100

Manufacturability

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

Machinability

68 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
65%

Weldability

90 / 100
88 / 100

Formability (cold)

80 / 100
70 / 100

Same in both: Castability 40 / 100 · Brazeability / Solderability 60 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 25 MJ/kg10,748 BTU/lb · Embodied Carbon (primary production) 2.1 kg CO₂/kg · Embodied Water 50 L/kg6 gal/lb · Typical Recycled Content 25%

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 scale20MnNb6

20MnNb6 +A vs 20MnNb6 +N — frequently asked

Is 20MnNb6 +N stronger than 20MnNb6 +A?

Yes. 20MnNb6 +N has a typical yield strength of 385 MPa (55.8 ksi) against 300 MPa (43.5 ksi) for 20MnNb6 +A — about 28% more. Tensile strength is 540 MPa (78.3 ksi) vs 470 MPa (68.2 ksi).

Which condition does FabDigit quote by default, +A or +N?

+N is the default 20MnNb6 condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, 20MnNb6 +A or 20MnNb6 +N?

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

Ready to make it?

Upload a CAD file and FabDigit prices the part in 20MnNb6 +A and 20MnNb6 +N 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.