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Steel X12Ni5-A vs X12Ni5-QT

Steel · X12Ni5 temper comparison

X12Ni5-A and X12Ni5-QT are two conditions of the same steel grade, X12Ni5: A (solution annealed) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. X12Ni5-QT is the stronger of the two: yield strength 440 MPa (63.8 ksi) against 340 MPa (49.3 ksi) for X12Ni5-A, about 29% more; tensile strength follows at 620 MPa (89.9 ksi) vs 520 MPa (75.4 ksi). In exchange, X12Ni5-A is the more ductile: elongation 28% versus 24% for X12Ni5-QT, and X12Ni5-QT is harder (185 HB vs 155 HB).

X12Ni5-AChoose it when the part is bent, formed or impact-loaded.

X12Ni5-QTChoose it when strength drives the design.

X12Ni5-A vs X12Ni5-QT: properties

X12Ni5-AX12Ni5-QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

520 MPa75.4 ksi
620 MPa89.9 ksi

Yield Strength (0.2% offset)

340 MPa49.3 ksi
440 MPa63.8 ksi

Elongation at Break

28%
24%

Reduction in Area

62%
60%

Compressive Strength

340 MPa49.3 ksi
440 MPa63.8 ksi

Shear Strength

320 MPa46.4 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

235 MPa34.1 ksi
280 MPa40.6 ksi

Fracture Toughness (K_IC)

120 MPa·√m109 ksi·√in
170 MPa·√m155 ksi·√in

Charpy V-Notch Impact (RT)

120 J88.5 ft·lbf
180 J133 ft·lbf

Hardness, Brinell

155 HB
185 HB

Hardness, Rockwell B

82 HRB
90 HRB

Hardness, Vickers

163 HV
195 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 Msi · Shear Modulus 79 GPa11.5 Msi · Bulk Modulus 165 GPa23.9 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) 1,440°C2,624 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

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

Thermal Conductivity

34 W/m·K19.6 BTU/hr·ft·°F
33 W/m·K19.1 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.2 µm/m·K6.2 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 350°C662 °F · Min Service Temperature -120°C-184 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

6.4 % IACS
6.2 % IACS

Electrical Resistivity

2.7×10⁻⁷ Ω·m10.6 µΩ·in
2.8×10⁻⁷ Ω·m11 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 16 / 100

Manufacturability

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

Machinability

60 / 100
52 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
55%

Weldability

72 / 100
68 / 100

Formability (cold)

70 / 100
62 / 100

Same in both: Brazeability / Solderability 55 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 38 MJ/kg16,337 BTU/lb · Embodied Carbon (primary production) 3 kg CO₂/kg · Embodied Water 65 L/kg7.8 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 scaleX12Ni5

X12Ni5-A vs X12Ni5-QT — frequently asked

Is X12Ni5-QT stronger than X12Ni5-A?

Yes. X12Ni5-QT has a typical yield strength of 440 MPa (63.8 ksi) against 340 MPa (49.3 ksi) for X12Ni5-A — about 29% more. Tensile strength is 620 MPa (89.9 ksi) vs 520 MPa (75.4 ksi).

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

QT is the default X12Ni5 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, X12Ni5-A or X12Ni5-QT?

X12Ni5-A. Its machinability rates good (60/100) against fair (52/100) for X12Ni5-QT.

Ready to make it?

Upload a CAD file and FabDigit prices the part in X12Ni5-A and X12Ni5-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.