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Steel HSLA-N vs HSLA-QT

Steel · HSLA temper comparison

HSLA-N and HSLA-QT are two conditions of the same steel grade, HSLA: N (normalized) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. HSLA-QT is the stronger of the two: yield strength 620 MPa (89.9 ksi) against 360 MPa (52.2 ksi) for HSLA-N, about 72% more; tensile strength follows at 720 MPa (104 ksi) vs 510 MPa (74 ksi). In exchange, HSLA-N is the more ductile: elongation 23% versus 18% for HSLA-QT, and HSLA-QT is harder (235 HB vs 155 HB). HSLA-N runs hotter in service (400°C vs 350°C continuous). On the shop floor, HSLA-N welds better (very good vs good).

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

HSLA-QTChoose it when strength drives the design.

HSLA-N vs HSLA-QT: properties

HSLA-NHSLA-QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

510 MPa74 ksi
720 MPa104 ksi

Yield Strength (0.2% offset)

360 MPa52.2 ksi
620 MPa89.9 ksi

Elongation at Break

23%
18%

Reduction in Area

52%
50%

Compressive Strength

360 MPa52.2 ksi
345 MPa50 ksi

Shear Strength

310 MPa45 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
340 MPa49.3 ksi

Fracture Toughness (K_IC)

110 MPa·√m100 ksi·√in
120 MPa·√m109 ksi·√in

Charpy V-Notch Impact (RT)

70 J51.6 ft·lbf
90 J66.4 ft·lbf

Hardness, Brinell

155 HB
235 HB

Hardness, Rockwell B

82 HRB
80 HRB

Hardness, Vickers

163 HV
158 HV

Same in both: Elastic (Young's) Modulus 205 GPa29.7 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 1,510°C2,750 °F

Thermal

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

Thermal Conductivity

46 W/m·K26.6 BTU/hr·ft·°F
45 W/m·K26 BTU/hr·ft·°F

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Min Service Temperature

-50°C-58 °F
-60°C-76 °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 270 J/g116 BTU/lb

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 9 % IACS · Electrical Resistivity 1.9×10⁻⁷ Ω·m7.48 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.61 V · Corrosion Resistance 16 / 100

Manufacturability

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

Machinability

60 / 100
58 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
45%

Weldability

82 / 100
65 / 100

Formability (cold)

62 / 100
40 / 100

Same in both: Castability 30 / 100 · Brazeability / Solderability 60 / 100 · Polishability 50 / 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 45 L/kg5.4 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 scaleHSLA

HSLA-N vs HSLA-QT — frequently asked

Is HSLA-QT stronger than HSLA-N?

Yes. HSLA-QT has a typical yield strength of 620 MPa (89.9 ksi) against 360 MPa (52.2 ksi) for HSLA-N — about 72% more. Tensile strength is 720 MPa (104 ksi) vs 510 MPa (74 ksi).

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

HR is the default HSLA condition in the FabDigit quote flow (neither N nor QT). 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 welds better, HSLA-N or HSLA-QT?

HSLA-N. Its weldability rates very good (82/100) against good (65/100) for HSLA-QT.

Ready to make it?

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