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Steel 30MnB5 +N vs 30MnB5 +QT

Steel · 30MnB5 temper comparison

30MnB5 +N and 30MnB5 +QT are two conditions of the same steel grade, 30MnB5: +N (normalized) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 30MnB5 +QT is the stronger of the two: yield strength 900 MPa (131 ksi) against 430 MPa (62.4 ksi) for 30MnB5 +N, about 109% more; tensile strength follows at 1,100 MPa (160 ksi) vs 680 MPa (98.6 ksi). In exchange, 30MnB5 +N is the more ductile: elongation 18% versus 12% for 30MnB5 +QT, and 30MnB5 +QT is harder (330 HB vs 205 HB). 30MnB5 +N runs hotter in service (400°C vs 300°C continuous) and 30MnB5 +N conducts electricity better (9 % IACS vs 8 % IACS). On the shop floor, 30MnB5 +N machines more easily (good vs fair).

30MnB5 +NChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

30MnB5 +QTChoose it when strength drives the design.

30MnB5 +N vs 30MnB5 +QT: properties

30MnB5 +N30MnB5 +QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

680 MPa98.6 ksi
1,100 MPa160 ksi

Yield Strength (0.2% offset)

430 MPa62.4 ksi
900 MPa131 ksi

Elongation at Break

18%
12%

Reduction in Area

52%
48%

Compressive Strength

600 MPa87 ksi
950 MPa138 ksi

Shear Strength

410 MPa59.5 ksi
660 MPa95.7 ksi

Fatigue Strength (Endurance Limit)

320 MPa46.4 ksi
500 MPa72.5 ksi

Fracture Toughness (K_IC)

65 MPa·√m59.2 ksi·√in
75 MPa·√m68.3 ksi·√in

Charpy V-Notch Impact (RT)

40 J29.5 ft·lbf
45 J33.2 ft·lbf

Hardness, Brinell

205 HB
330 HB

Hardness, Rockwell C

14 HRC
35 HRC

Hardness, Vickers

215 HV
345 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 80 GPa11.6 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) 1,425°C2,597 °F · Liquidus Temperature 1,495°C2,723 °F

Thermal

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

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
44 W/m·K25.4 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
300°C572 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 12.3 µm/m·K6.8 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -20°C-4 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

9 % IACS
8 % IACS

Electrical Resistivity

1.95×10⁻⁷ Ω·m7.68 µΩ·in
2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.65 V · Corrosion Resistance 10 / 100

Manufacturability

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

Machinability

56 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
45%

Weldability

35 / 100
30 / 100

Formability (cold)

55 / 100
35 / 100

Same in both: Brazeability / Solderability 50 / 100 · Polishability 60 / 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 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 30%

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 scale30MnB5

30MnB5 +N vs 30MnB5 +QT — frequently asked

Is 30MnB5 +QT stronger than 30MnB5 +N?

Yes. 30MnB5 +QT has a typical yield strength of 900 MPa (131 ksi) against 430 MPa (62.4 ksi) for 30MnB5 +N — about 109% more. Tensile strength is 1,100 MPa (160 ksi) vs 680 MPa (98.6 ksi).

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

+QT is the default 30MnB5 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, 30MnB5 +N or 30MnB5 +QT?

30MnB5 +N. Its machinability rates good (56/100) against fair (40/100) for 30MnB5 +QT; for welding the order is 30MnB5 +N first (fair, 35/100) then 30MnB5 +QT (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 30MnB5 +N and 30MnB5 +QT 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.