Aluminum AC7A F-S vs AC7A-O
Aluminum · AC7A temper comparison
AC7A F-S and AC7A-O are two conditions of the same aluminum grade, AC7A: F-S (f) versus O (annealed). The chemistry is identical, so every difference below comes from the condition. AC7A F-S is the stronger of the two: yield strength 85 MPa (12.3 ksi) against 75 MPa (10.9 ksi) for AC7A-O, about 13% more; tensile strength follows at 170 MPa (24.7 ksi) vs 160 MPa (23.2 ksi). In exchange, AC7A-O is the more ductile: elongation 12% versus 9% for AC7A F-S, and AC7A F-S is harder (50 HB vs 46 HB).
AC7A F-SChoose it when strength drives the design.
AC7A-OChoose it when the part is bent, formed or impact-loaded.
AC7A F-S vs AC7A-O: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum 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 aluminum 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.
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)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 71 GPa10.3 Msi · Shear Modulus 26.5 GPa3.8 Msi · Bulk Modulus 69 GPa10 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Same in both: Density 2.65 g/cm³0.1 lb/in³ · Melting Point (Solidus) 599°C1,110 °F · Liquidus Temperature 638°C1,180 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Same in both: Specific Heat Capacity 900 J/kg·K0.21 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 24.3 µm/m·K13.5 µin/in·°F · Latent Heat of Fusion 390 J/g168 BTU/lb · Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.87 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Same in both: Weldability 80 / 100 · Castability 35 / 100 · Brazeability / Solderability 15 / 100 · Polishability 90 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg · Embodied Water 1,150 L/kg138 gal/lb · Typical Recycled Content 55%
Strength versus weight
Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
AC7A F-S vs AC7A-O — frequently asked
Is AC7A F-S stronger than AC7A-O?
Yes. AC7A F-S has a typical yield strength of 85 MPa (12.3 ksi) against 75 MPa (10.9 ksi) for AC7A-O — about 13% more. Tensile strength is 170 MPa (24.7 ksi) vs 160 MPa (23.2 ksi).
Which condition does FabDigit quote by default, F-S or O?
F-S is the default AC7A 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 AC7A F-S over AC7A-O?
Pick AC7A F-S when strength drives the design. Pick AC7A-O when the part is bent, formed or impact-loaded.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AC7A F-S and AC7A-O 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.