Aluminum AC7A
JIS AC7A
AC7A is a JIS Al-Mg (AlMg5) casting alloy with magnesium in solid solution and essentially no silicon, matching A514.0 and EN AC-51000.
Reference datasheet — AC7A is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the F-S condition
AC7A tempers and conditions
AC7A is supplied in 3 conditions, soft to hard. F-S is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Optional low-temperature anneal used to relieve casting and machining stresses and stabilise dimensions; slightly lowers strength and hardness. | 75 | 160 | 12 | 46 HB | 36 % IACS |
F-SDefault F | Standard supply condition for AC7A sand castings — marine fittings, decorative and food-contact parts needing corrosion resistance and polish. | 85 | 170 | 9 | 50 HB | 35 % IACS |
F | Choose for thinner, finer-grained sections and slightly higher strength/hardness than sand casting, in the same as-cast F condition. | 95 | 190 | 12 | 55 HB | 35 % IACS |
What is AC7A?
AC7A is a JIS Al-Mg (AlMg5) casting alloy with magnesium in solid solution and essentially no silicon, matching A514.0 and EN AC-51000. Engineers select it for corrosion resistance and a polishable, silicon-free surface, with typical as-cast values of 170 MPa tensile, 85 MPa yield, 9% elongation, 50 HB and 138 W/m·K, supplied as sand or permanent-mould castings in F-S, F-P and O conditions. The trade-off is castability: low fluidity, heavy melt oxidation and hot-tearing tendency restrict thin, intricate sections, and service is limited to about 120 °C. Where castability outweighs appearance, an Al-Si alloy is the usual substitute. AC7A has a density of 2.65 g/cm³ (0.0957 lb/in³), lighter than 90% of aluminum grades. It melts at 599°C (1,110 °F). AC7A has a yield strength of 85 MPa (12.3 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 88% of aluminum grades. Elongation at break is 9% and the elastic modulus is 71 GPa (10.3 Msi).
What is AC7A used for?
- marine fittings
- decorative hardware
- food equipment parts
- architectural castings
Advantages
- Polishes to a fine finish — 90/100, better than 98% of aluminum grades
- Good corrosion resistance — 78/100, better than 94% of aluminum grades
Limitations
- Low strength — 85 MPa (12.3 ksi), worse than 88% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
AC7A properties
Typical room-temperature values for AC7A-F-S; bars are the position among aluminum grades.
Physical3
AC7A has a density of 2.65 g/cm³ (0.0957 lb/in³), lighter than 90% of aluminum grades. It melts at 599°C (1,110 °F).
Mechanical12
AC7A has a yield strength of 85 MPa (12.3 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 88% of aluminum grades. Elongation at break is 9% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
AC7A is rated for continuous service to 120°C (248 °F). It conducts heat at 138 W/m·K (79.7 BTU/hr·ft·°F), worse than 55% of aluminum grades. Thermal expansion is 24.3 µm/m·K (13.5 µin/in·°F).
Electrical3
AC7A conducts electricity at 35 % IACS, better than 52% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 94% of aluminum grades.
Sustainability4
Producing a kilogram of AC7A takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 55%.
Manufacturability7
AC7A's machinability is very good (70/100, better than 72% of aluminum grades); weldability very good (80/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. AC7A is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AC7A
Is AC7A easy to machine?
Machines cleanly but is gummy — use sharp polished-flute carbide tools, high rake, high speed and generous coolant to avoid built-up edge and smeared surfaces.
Can AC7A be welded?
Readily TIG/MIG welded with 5356 or 5183 filler; no post-weld heat treatment required and weld corrosion resistance matches the base metal.
Can AC7A be formed, bent or molded?
Difficult to cast: low fluidity, heavy melt oxidation and hot-tearing tendency — use flux/cover gas or SF6-free protective melting, chills, generous risers and fast controlled pouring; avoid thin intricate sections.
AC7A chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Mgprimary strengthening/solid-solution element | 3.5 – 5.5 | 4.5 |
| Sikept low for bright anodizing | ≤ 0.2 | 0.1 |
| Fe | ≤ 0.3 | 0.15 |
| Culimited to protect corrosion resistance | ≤ 0.1 | 0.03 |
| Mn | ≤ 0.6 | 0.15 |
| Ni | ≤ 0.05 | |
| Zn | ≤ 0.15 | |
| Tigrain refiner | ≤ 0.2 | 0.1 |
| Pb | ≤ 0.05 | |
| Sn | ≤ 0.05 | |
| Croptional, per equivalent EN AC-51000 | ≤ 0.15 | |
| Al | balance |
What surface finishes work on AC7A?
Ideal for bright/decorative and clear anodizing and for high mechanical polish thanks to very low Si; also takes chemical conversion coating and paint well.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum AC7A in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does AC7A cost?
AC7A is a standard-cost aluminum ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
AC7A — frequently asked
What is AC7A used for?
AC7A is typically used for marine fittings, decorative hardware, food equipment parts and architectural castings. In short: most corrosion-resistant AC grade; polishable silicon-free casting; poor castability trade-off.
What is the yield strength of AC7A?
AC7A has a typical yield strength of 85 MPa (12.3 ksi) and a tensile strength of 170 MPa (24.7 ksi) — weaker than 88% of aluminum grades. Strength varies by condition: see the 3 listed tempers.
Is AC7A easy to machine?
Yes — machinability is rated very good (70/100, better than 72% of aluminum grades). Machines cleanly but is gummy — use sharp polished-flute carbide tools, high rake, high speed and generous coolant to avoid built-up edge and smeared surfaces.
Can AC7A be welded?
Yes — weldability is rated very good (80/100). Readily TIG/MIG welded with 5356 or 5183 filler; no post-weld heat treatment required and weld corrosion resistance matches the base metal.
What surface finishes work on AC7A?
Ideal for bright/decorative and clear anodizing and for high mechanical polish thanks to very low Si; also takes chemical conversion coating and paint well.
Can AC7A be formed, bent or molded?
Difficult to cast: low fluidity, heavy melt oxidation and hot-tearing tendency — use flux/cover gas or SF6-free protective melting, chills, generous risers and fast controlled pouring; avoid thin intricate sections.
What is the maximum service temperature of AC7A?
AC7A is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AC7A F-S and AC7A F-P?
F-S is the default condition — standard supply condition for AC7A sand castings — marine fittings, decorative and food-contact parts needing corrosion resistance and polish. F-P: choose for thinner, finer-grained sections and slightly higher strength/hardness than sand casting, in the same as-cast F condition. Yield strength is 85 MPa in F-S versus 95 MPa in F-P.
How much does AC7A cost?
AC7A is a standard-cost aluminum ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- JIS H5202 — Aluminium alloy castings — Japanese Standards Association (2010)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (514.0) — ASM International (1990)
- EN 1706 — Aluminium and aluminium alloys, castings (EN AC-51000 AlMg3 / AlMg5 family) — CEN (2020)
- Aluminum Association Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot — The Aluminum Association (2019)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.