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Steel A356 Grade 9 Annealed vs A356 Grade 9 Q+T

Steel · A356 Grade 9 temper comparison

A356 Grade 9 Annealed and A356 Grade 9 Q+T are two conditions of the same steel grade, A356 Grade 9: Annealed 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 330 MPa (47.9 ksi) for A356 Grade 9 Annealed, about 64% more; tensile strength follows at 740 MPa (107 ksi) vs 570 MPa (82.7 ksi). In exchange, A356 Grade 9 Annealed is the more ductile: elongation 26% versus 19% for A356 Grade 9 Q+T, and A356 Grade 9 Q+T is harder (225 HB vs 165 HB). A356 Grade 9 Q+T runs hotter in service (600°C vs 500°C continuous). On the shop floor, A356 Grade 9 Annealed machines more easily (good vs fair).

A356 Grade 9 AnnealedChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

A356 Grade 9 Q+TChoose it when strength drives the design, or when the part sees heat.

A356 Grade 9 Annealed vs A356 Grade 9 Q+T: properties

A356 Grade 9 AnnealedA356 Grade 9 Q+T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

570 MPa82.7 ksi
740 MPa107 ksi

Yield Strength (0.2% offset)

330 MPa47.9 ksi
540 MPa78.3 ksi

Elongation at Break

26%
19%

Reduction in Area

58%
52%

Compressive Strength

330 MPa47.9 ksi
480 MPa69.6 ksi

Shear Strength

360 MPa52.2 ksi
420 MPa60.9 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
320 MPa46.4 ksi

Fracture Toughness (K_IC)

115 MPa·√m105 ksi·√in
100 MPa·√m91 ksi·√in

Hardness, Brinell

165 HB
225 HB

Hardness, Rockwell B

85 HRB
93 HRB

Hardness, Rockwell C

14 HRC
21 HRC

Hardness, Vickers

173 HV
210 HV

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 · Charpy V-Notch Impact (RT) 60 J44.3 ft·lbf

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.

Thermal Conductivity

28 W/m·K16.2 BTU/hr·ft·°F
27 W/m·K15.6 BTU/hr·ft·°F

Max Service Temperature (continuous)

500°C932 °F
600°C1,112 °F

Same in both: 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 · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

3 % IACS
2.9 % IACS

Electrical Resistivity

5.8×10⁻⁷ Ω·m22.8 µΩ·in
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

55 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
42%

Weldability

45 / 100
40 / 100

Formability (cold)

20 / 100
10 / 100

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.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleA356 Grade 9

A356 Grade 9 Annealed vs A356 Grade 9 Q+T — frequently asked

Is A356 Grade 9 Q+T stronger than A356 Grade 9 Annealed?

Yes. A356 Grade 9 Q+T has a typical yield strength of 540 MPa (78.3 ksi) against 330 MPa (47.9 ksi) for A356 Grade 9 Annealed — about 64% more. Tensile strength is 740 MPa (107 ksi) vs 570 MPa (82.7 ksi).

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

N+T is the default A356 Grade 9 condition in the FabDigit quote flow (neither Annealed 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.

Which is easier to machine, A356 Grade 9 Annealed or A356 Grade 9 Q+T?

A356 Grade 9 Annealed. Its machinability rates good (55/100) against fair (45/100) for A356 Grade 9 Q+T; for welding the order is A356 Grade 9 Annealed first (fair, 45/100) then A356 Grade 9 Q+T (fair, 40/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in A356 Grade 9 Annealed 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.