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Steel 12KhN3A-N vs 12KhN3A-QT

Steel · 12KhN3A temper comparison

12KhN3A-N and 12KhN3A-QT are two conditions of the same steel grade, 12KhN3A: N (normalized) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. 12KhN3A-QT is the stronger of the two: yield strength 760 MPa (110 ksi) against 520 MPa (75.4 ksi) for 12KhN3A-N, about 46% more; tensile strength follows at 980 MPa (142 ksi) vs 760 MPa (110 ksi). In exchange, 12KhN3A-N is the more ductile: elongation 18% versus 13% for 12KhN3A-QT, and 12KhN3A-QT is harder (285 HB vs 230 HB). 12KhN3A-N runs hotter in service (350°C vs 200°C continuous). On the shop floor, 12KhN3A-N machines more easily (50 vs 40 out of 100) and 12KhN3A-N welds better (50 vs 40 out of 100).

12KhN3A-NChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

12KhN3A-QTChoose it when strength drives the design.

12KhN3A-N vs 12KhN3A-QT: properties

12KhN3A-N12KhN3A-QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

760 MPa110 ksi
980 MPa142 ksi

Yield Strength (0.2% offset)

520 MPa75.4 ksi
760 MPa110 ksi

Elongation at Break

18%
13%

Reduction in Area

55%
58%

Compressive Strength

530 MPa76.9 ksi
780 MPa113 ksi

Shear Strength

460 MPa66.7 ksi
600 MPa87 ksi

Fatigue Strength (Endurance Limit)

350 MPa50.8 ksi
480 MPa69.6 ksi

Fracture Toughness (K_IC)

115 MPa·√m105 ksi·√in
95 MPa·√m86.5 ksi·√in

Charpy V-Notch Impact (RT)

75 J55.3 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

230 HB
285 HB

Hardness, Rockwell C

20 HRC
30 HRC

Hardness, Vickers

242 HV
300 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

39 W/m·K22.5 BTU/hr·ft·°F
38 W/m·K22 BTU/hr·ft·°F

Max Service Temperature (continuous)

350°C662 °F
200°C392 °F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.4 µm/m·K6.3 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -70°C-94 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

7.5 % IACS
7 % IACS

Electrical Resistivity

2.3×10⁻⁷ Ω·m9.06 µΩ·in
2.6×10⁻⁷ Ω·m10.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.62 V · Corrosion Resistance 13 / 100

Manufacturability

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

Machinability

50 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

50%
45%

Weldability

50 / 100
40 / 100

Formability (cold)

50 / 100
45 / 100

Same in both: Brazeability / Solderability 55 / 100 · Polishability 70 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.5 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 scale12KhN3A

12KhN3A-N vs 12KhN3A-QT — frequently asked

Is 12KhN3A-QT stronger than 12KhN3A-N?

Yes. 12KhN3A-QT has a typical yield strength of 760 MPa (110 ksi) against 520 MPa (75.4 ksi) for 12KhN3A-N — about 46% more. Tensile strength is 980 MPa (142 ksi) vs 760 MPa (110 ksi).

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

QT is the default 12KhN3A 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, 12KhN3A-N or 12KhN3A-QT?

12KhN3A-N, by a small margin. Both rate fair for machinability — 50/100 against 40/100 for 12KhN3A-QT; for welding the order is 12KhN3A-N first (fair, 50/100) then 12KhN3A-QT (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 12KhN3A-N and 12KhN3A-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.