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Steel A356 Grade 9 Annealed vs A356 Grade 9 N+T+SR

Steel · A356 Grade 9 temper comparison

A356 Grade 9 Annealed and A356 Grade 9 N+T+SR are two conditions of the same steel grade, A356 Grade 9: Annealed versus N+T+SR (N+T + post-weld heat treatment / stress relief). The chemistry is identical, so every difference below comes from the condition. A356 Grade 9 N+T+SR is the stronger of the two: yield strength 455 MPa (66 ksi) against 330 MPa (47.9 ksi) for A356 Grade 9 Annealed, about 38% more; tensile strength follows at 660 MPa (95.7 ksi) vs 570 MPa (82.7 ksi). In exchange, A356 Grade 9 Annealed is the more ductile: elongation 26% versus 21% for A356 Grade 9 N+T+SR, and A356 Grade 9 N+T+SR is harder (190 HB vs 165 HB). A356 Grade 9 N+T+SR runs hotter in service (600°C vs 500°C continuous).

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

A356 Grade 9 N+T+SRChoose it when strength drives the design, or when the part sees heat.

A356 Grade 9 Annealed vs A356 Grade 9 N+T+SR: properties

A356 Grade 9 AnnealedA356 Grade 9 N+T+SR

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

570 MPa82.7 ksi
660 MPa95.7 ksi

Yield Strength (0.2% offset)

330 MPa47.9 ksi
455 MPa66 ksi

Elongation at Break

26%
21%

Reduction in Area

58%
52%

Compressive Strength

330 MPa47.9 ksi
455 MPa66 ksi

Shear Strength

360 MPa52.2 ksi
400 MPa58 ksi

Fatigue Strength (Endurance Limit)

250 MPa36.3 ksi
290 MPa42.1 ksi

Fracture Toughness (K_IC)

115 MPa·√m105 ksi·√in
110 MPa·√m100 ksi·√in

Charpy V-Notch Impact (RT)

60 J44.3 ft·lbf
55 J40.6 ft·lbf

Hardness, Brinell

165 HB
190 HB

Hardness, Rockwell B

85 HRB
91 HRB

Hardness, Rockwell C

14 HRC
11 HRC

Hardness, Vickers

173 HV
199 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

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
48 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
52%

Weldability

45 / 100
42 / 100

Formability (cold)

20 / 100
12 / 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 N+T+SR — frequently asked

Is A356 Grade 9 N+T+SR stronger than A356 Grade 9 Annealed?

Yes. A356 Grade 9 N+T+SR has a typical yield strength of 455 MPa (66 ksi) against 330 MPa (47.9 ksi) for A356 Grade 9 Annealed — about 38% more. Tensile strength is 660 MPa (95.7 ksi) vs 570 MPa (82.7 ksi).

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

N+T is the default A356 Grade 9 condition in the FabDigit quote flow (neither Annealed nor N+T+SR). 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 N+T+SR?

A356 Grade 9 Annealed. Its machinability rates good (55/100) against fair (48/100) for A356 Grade 9 N+T+SR.

Ready to make it?

Upload a CAD file and FabDigit prices the part in A356 Grade 9 Annealed and A356 Grade 9 N+T+SR 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.