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Steel A302 N+T vs A302-QT

Steel · A302 temper comparison

A302 N+T and A302-QT are two conditions of the same steel grade, A302: N+T (normalized and tempered) versus QT (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. A302-QT is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 395 MPa (57.3 ksi) for A302 N+T, about 22% more; tensile strength follows at 640 MPa (92.8 ksi) vs 575 MPa (83.4 ksi). In exchange, A302 N+T is the more ductile: elongation 24% versus 21% for A302-QT, and A302-QT is harder (205 HB vs 175 HB).

A302 N+TChoose it when the part is bent, formed or impact-loaded.

A302-QTChoose it when strength drives the design.

A302 N+T vs A302-QT: properties

A302 N+TA302-QT

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

575 MPa83.4 ksi
640 MPa92.8 ksi

Yield Strength (0.2% offset)

395 MPa57.3 ksi
480 MPa69.6 ksi

Elongation at Break

24%
21%

Reduction in Area

58%
62%

Compressive Strength

395 MPa57.3 ksi
400 MPa58 ksi

Shear Strength

370 MPa53.7 ksi
380 MPa55.1 ksi

Fatigue Strength (Endurance Limit)

260 MPa37.7 ksi
300 MPa43.5 ksi

Fracture Toughness (K_IC)

165 MPa·√m150 ksi·√in
200 MPa·√m182 ksi·√in

Charpy V-Notch Impact (RT)

95 J70.1 ft·lbf
130 J95.9 ft·lbf

Hardness, Brinell

175 HB
205 HB

Hardness, Rockwell B

87 HRB
89 HRB

Hardness, Vickers

184 HV
215 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 1,505°C2,741 °F

Thermal

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

Min Service Temperature

-35°C-31 °F
-50°C-58 °F

Same in both: Thermal Conductivity 41 W/m·K23.7 BTU/hr·ft·°F · 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 250 J/g107 BTU/lb · Max Service Temperature (continuous) 450°C842 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 7.8 % IACS · Electrical Resistivity 2.2×10⁻⁷ Ω·m8.66 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.6 V · Corrosion Resistance 12 / 100

Manufacturability

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

Machinability

57 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

62%
52%

Weldability

72 / 100
65 / 100

Formability (cold)

58 / 100
55 / 100

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

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 30 MJ/kg12,898 BTU/lb · Embodied Carbon (primary production) 2.2 kg CO₂/kg · Embodied Water 60 L/kg7.2 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 scaleA302

A302 N+T vs A302-QT — frequently asked

Is A302-QT stronger than A302 N+T?

Yes. A302-QT has a typical yield strength of 480 MPa (69.6 ksi) against 395 MPa (57.3 ksi) for A302 N+T — about 22% more. Tensile strength is 640 MPa (92.8 ksi) vs 575 MPa (83.4 ksi).

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

GrB-N is the default A302 condition in the FabDigit quote flow (neither N+T 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, A302 N+T or A302-QT?

A302 N+T. Its weldability rates very good (72/100) against good (65/100) for A302-QT.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A302 N+T and A302-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.