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Steel P255QL +N vs P255QL +QT

Steel · P255QL temper comparison

P255QL +N and P255QL +QT are two conditions of the same steel grade, P255QL: +N (normalized) versus +QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. P255QL +QT is the stronger of the two: yield strength 290 MPa (42.1 ksi) against 270 MPa (39.2 ksi) for P255QL +N, about 7% more. P255QL +QT is harder — 135 HB against 125 HB for P255QL +N — which matters for wear surfaces and threads.

P255QL +QTChoose it when strength drives the design, or when surface hardness matters.

P255QL +N vs P255QL +QT: properties

P255QL +NP255QL +QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

400 MPa58 ksi
420 MPa60.9 ksi

Yield Strength (0.2% offset)

270 MPa39.2 ksi
290 MPa42.1 ksi

Elongation at Break

30%
28%

Reduction in Area

62%
60%

Compressive Strength

270 MPa39.2 ksi
290 MPa42.1 ksi

Shear Strength

250 MPa36.3 ksi
270 MPa39.2 ksi

Fatigue Strength (Endurance Limit)

180 MPa26.1 ksi
190 MPa27.6 ksi

Fracture Toughness (K_IC)

100 MPa·√m91 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

110 J81.1 ft·lbf
130 J95.9 ft·lbf

Hardness, Brinell

125 HB
135 HB

Hardness, Rockwell B

70 HRB
74 HRB

Hardness, Vickers

131 HV
142 HV

Same in both: Elastic (Young's) Modulus 210 GPa30.5 Msi · Shear Modulus 81 GPa11.7 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) 1,460°C2,660 °F · Liquidus Temperature 1,510°C2,750 °F

Thermal

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

Thermal Conductivity

49 W/m·K28.3 BTU/hr·ft·°F
48 W/m·K27.7 BTU/hr·ft·°F

Same in both: Specific Heat Capacity 460 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 · Max Service Temperature (continuous) 300°C572 °F · Min Service Temperature -50°C-58 °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) -0.65 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

67 / 100
65 / 100

Machinability Rating (AISI 1212 = 100 %)

72%
70%

Weldability

92 / 100
90 / 100

Formability (cold)

78 / 100
70 / 100

Same in both: Brazeability / Solderability 55 / 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) 2 kg CO₂/kg · Embodied Water 45 L/kg5.4 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 scaleP255QL

P255QL +N vs P255QL +QT — frequently asked

Is P255QL +QT stronger than P255QL +N?

Yes. P255QL +QT has a typical yield strength of 290 MPa (42.1 ksi) against 270 MPa (39.2 ksi) for P255QL +N — about 7% more. Tensile strength is 420 MPa (60.9 ksi) vs 400 MPa (58 ksi).

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

+QT is the default P255QL 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 P255QL +N over P255QL +QT?

Pick P255QL +QT when strength drives the design, or when surface hardness matters.

Ready to make it?

Upload a CAD file and FabDigit prices the part in P255QL +N and P255QL +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.