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Steel LCA N+T vs LCA Q+T

Steel · LCA temper comparison

LCA N+T and LCA Q+T are two conditions of the same steel grade, LCA: N+T (normalized and tempered) versus Q+T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. LCA Q+T is the stronger of the two: yield strength 290 MPa (42.1 ksi) against 250 MPa (36.3 ksi) for LCA N+T, about 16% more; tensile strength follows at 505 MPa (73.2 ksi) vs 470 MPa (68.2 ksi). LCA Q+T is harder — 163 HB against 150 HB for LCA N+T — which matters for wear surfaces and threads.

LCA Q+TChoose it when strength drives the design, or when surface hardness matters.

LCA N+T vs LCA Q+T: properties

LCA N+TLCA Q+T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

470 MPa68.2 ksi
505 MPa73.2 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
290 MPa42.1 ksi

Elongation at Break

30%
28%

Reduction in Area

45%
50%

Fatigue Strength (Endurance Limit)

200 MPa29 ksi
215 MPa31.2 ksi

Charpy V-Notch Impact (RT)

55 J40.6 ft·lbf
70 J51.6 ft·lbf

Hardness, Brinell

150 HB
163 HB

Hardness, Rockwell B

80 HRB
84 HRB

Same in both: Elastic (Young's) Modulus 200 GPa29 Msi · Shear Modulus 78 GPa11.3 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Compressive Strength 250 MPa36.3 ksi · Shear Strength 300 MPa43.5 ksi · Fracture Toughness (K_IC) 70 MPa·√m63.7 ksi·√in

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 1,510°C2,750 °F

Thermal

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

Same in both: Thermal Conductivity 50 W/m·K28.9 BTU/hr·ft·°F · Specific Heat Capacity 470 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.9 µm/m·K6.6 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 425°C797 °F · Min Service Temperature -32°C-26 °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) -0.61 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

60%
55%

Same in both: Machinability 58 / 100 · Weldability 85 / 100 · Formability (cold) 20 / 100 · Castability 75 / 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) 1.9 kg CO₂/kg · Embodied Water 50 L/kg6 gal/lb · Typical Recycled Content 80%

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 scaleLCA

LCA N+T vs LCA Q+T — frequently asked

Is LCA Q+T stronger than LCA N+T?

Yes. LCA Q+T has a typical yield strength of 290 MPa (42.1 ksi) against 250 MPa (36.3 ksi) for LCA N+T — about 16% more. Tensile strength is 505 MPa (73.2 ksi) vs 470 MPa (68.2 ksi).

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

N+T is the default LCA 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.

When should I choose LCA N+T over LCA Q+T?

Pick LCA Q+T when strength drives the design, or when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in LCA N+T and LCA Q+T 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.