Steel A356 Grade 9 N+T+SR vs A356 Grade 9 Q+T
Steel · A356 Grade 9 temper comparison
A356 Grade 9 N+T+SR and A356 Grade 9 Q+T are two conditions of the same steel grade, A356 Grade 9: N+T+SR (N+T + post-weld heat treatment / stress relief) versus Q+T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. A356 Grade 9 Q+T is the stronger of the two: yield strength 540 MPa (78.3 ksi) against 455 MPa (66 ksi) for A356 Grade 9 N+T+SR, about 19% more; tensile strength follows at 740 MPa (107 ksi) vs 660 MPa (95.7 ksi). A356 Grade 9 Q+T is harder — 225 HB against 190 HB for A356 Grade 9 N+T+SR — which matters for wear surfaces and threads.
A356 Grade 9 Q+TChoose it when strength drives the design, or when surface hardness matters.
A356 Grade 9 N+T+SR vs A356 Grade 9 Q+T: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all steel grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
A356 Grade 9 N+T+SRA356 Grade 9 Q+T
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Hardness, Rockwell C
Hardness, Vickers
Same in both: Elastic (Young's) Modulus 207 GPa30 Msi · Shear Modulus 80 GPa11.6 Msi · Bulk Modulus 160 GPa23.2 Msi · Poisson's Ratio 0.29 · Reduction in Area 52%
Physical
Density and transition temperatures.
Same in both: Density 7.78 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,420°C2,588 °F · Liquidus Temperature 1,495°C2,723 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 27 W/m·K15.6 BTU/hr·ft·°F · Specific Heat Capacity 460 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 11.3 µm/m·K6.3 µin/in·°F · Latent Heat of Fusion 270 J/g116 BTU/lb · Max Service Temperature (continuous) 600°C1,112 °F · Min Service Temperature -30°C-22 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 2.9 % IACS · Electrical Resistivity 6×10⁻⁷ Ω·m23.6 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.55 V · Corrosion Resistance 30 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Castability 60 / 100 · Brazeability / Solderability 35 / 100 · Polishability 55 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 32 MJ/kg13,758 BTU/lb · Embodied Carbon (primary production) 2.4 kg CO₂/kg · Embodied Water 60 L/kg7.2 gal/lb · Typical Recycled Content 70%
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.
A356 Grade 9 N+T+SR vs A356 Grade 9 Q+T — frequently asked
Is A356 Grade 9 Q+T stronger than A356 Grade 9 N+T+SR?
Yes. A356 Grade 9 Q+T has a typical yield strength of 540 MPa (78.3 ksi) against 455 MPa (66 ksi) for A356 Grade 9 N+T+SR — about 19% more. Tensile strength is 740 MPa (107 ksi) vs 660 MPa (95.7 ksi).
Which condition does FabDigit quote by default, N+T+SR or Q+T?
N+T is the default A356 Grade 9 condition in the FabDigit quote flow (neither N+T+SR nor Q+T). 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 A356 Grade 9 N+T+SR over A356 Grade 9 Q+T?
Pick A356 Grade 9 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 A356 Grade 9 N+T+SR and A356 Grade 9 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.