Aluminum AC1A
JIS AC1A
AC1A is a JIS heat-treatable Al-Cu sand and permanent-mould casting alloy (AlCu4TiMg), cross-referenced to A201.0 and ZL201 and supplied in F, T4, T6 and T7.
Reference datasheet — AC1A 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 T6 condition
AC1A tempers and conditions
AC1A is supplied in 4 conditions, soft to hard. T6 is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest cost condition for non-critical parts or blanks that will be heat treated later; strength is modest and the structure is cored. | 95 | 165 | 5 | 55 HB | 36 % IACS |
Solution heat treated and naturally aged | Best combination of strength and ductility/toughness; choose when impact loading or elongation matters more than peak strength. | 180 | 295 | 8 | 70 HB | 27 % IACS |
Solution heat treated and overaged (stabilized) | Overaged for dimensional stability, better toughness and improved resistance to intergranular/stress-corrosion attack; used for parts running hot (150–250 °C). | 245 | 305 | 3.5 | 88 HB | 35 % IACS |
T6Default Solution heat treated and artificially aged | Standard high-strength condition for structural castings; pick it when maximum tensile/yield strength and hardness are required and ductility can be traded away. | 250 | 335 | 4 | 95 HB | 31 % IACS |
What is AC1A?
AC1A is a JIS heat-treatable Al-Cu sand and permanent-mould casting alloy (AlCu4TiMg), cross-referenced to A201.0 and ZL201 and supplied in F, T4, T6 and T7. Engineers select it where cast parts must carry high loads at temperature: 250 MPa yield, 335 MPa tensile, 4% elongation, 95 HB, service to 175 °C, 125 W/m·K thermal conductivity, 31% IACS and a machinability rating of 72. Castability is the trade-off, with high hot-tearing sensitivity, limited pressure tightness and a corrosion resistance score of only 33, so coating is required. Use an Al-Si alloy such as AC4C/A356 when fluidity and corrosion resistance outrank strength. AC1A has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 545°C (1,013 °F). AC1A has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 335 MPa (48.6 ksi) — stronger than 65% of aluminum grades. Elongation at break is 4% and the elastic modulus is 71 GPa (10.3 Msi).
What is AC1A used for?
- aircraft structural castings
- high-strength brackets
- engine mounts
Advantages
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Needs corrosion protection — 33/100, worse than 91% of aluminum grades
- Difficult to weld — 25/100, worse than 76% of aluminum grades
AC1A properties
Typical room-temperature values for AC1A-T6; bars are the position among aluminum grades.
Physical3
AC1A has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 545°C (1,013 °F).
Mechanical12
AC1A has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 335 MPa (48.6 ksi) — stronger than 65% of aluminum grades. Elongation at break is 4% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
AC1A is rated for continuous service to 175°C (347 °F). It conducts heat at 125 W/m·K (72.2 BTU/hr·ft·°F), worse than 72% of aluminum grades. Thermal expansion is 22.5 µm/m·K (12.5 µin/in·°F).
Electrical3
AC1A conducts electricity at 31 % IACS, worse than 68% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (33/100), worse than 91% of aluminum grades.
Sustainability4
Producing a kilogram of AC1A takes about 190 MJ of energy and emits 12.5 kg of CO₂ — less than 89% of aluminum grades. Typical recycled content is 20%.
Manufacturability7
AC1A's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (25/100).
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. AC1A is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AC1A
Is AC1A easy to machine?
Machines very well in T4/T6 with sharp carbide or PCD tooling, high speed and flood coolant; chips are short and finishes are good, but porosity can show up as surface pinholes.
Can AC1A be welded?
Poor fusion weldability — Al-Cu castings hot-tear readily; if repair welding is unavoidable use 2319 (Al-Cu) filler, preheat, and re-solution/re-age afterwards.
Can AC1A be formed, bent or molded?
Sand and permanent-mold casting only; needs strong directional solidification with generous risers, chills and controlled pouring to fight hot tearing and interdendritic shrinkage — low pressure-tightness.
AC1A 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 |
|---|---|---|
| Cumain strengthening element | 4 – 5 | 4.5 |
| Mg | 0.15 – 0.35 | 0.25 |
| Tigrain refiner | 0.05 – 0.3 | 0.2 |
| Siimpurity limit | ≤ 0.2 | |
| Feimpurity limit | ≤ 0.25 | |
| Mn | ≤ 0.1 | |
| Zn | ≤ 0.1 | |
| Ni | ≤ 0.05 | |
| Sn | ≤ 0.05 | |
| Pb | ≤ 0.05 | |
| Al | balance |
What surface finishes work on AC1A?
Painting or chromate/anodize-plus-seal is normally required for corrosion protection; hard anodize is feasible but films are dark and uneven due to the copper, and polished surfaces are limited by microporosity.
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 AC1A in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does AC1A cost?
AC1A is a premium-cost aluminum ($$$), cheaper than about 51% 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.
AC1A — frequently asked
What is AC1A used for?
AC1A is typically used for aircraft structural castings, high-strength brackets and engine mounts. In short: highest-strength cast aluminum; heat-treatable Al-Cu casting alloy; difficult to cast.
What is the yield strength of AC1A?
AC1A has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 335 MPa (48.6 ksi) — stronger than 65% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is AC1A easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines very well in T4/T6 with sharp carbide or PCD tooling, high speed and flood coolant; chips are short and finishes are good, but porosity can show up as surface pinholes.
Can AC1A be welded?
Not readily — weldability is rated poor (25/100). Poor fusion weldability — Al-Cu castings hot-tear readily; if repair welding is unavoidable use 2319 (Al-Cu) filler, preheat, and re-solution/re-age afterwards.
What surface finishes work on AC1A?
Painting or chromate/anodize-plus-seal is normally required for corrosion protection; hard anodize is feasible but films are dark and uneven due to the copper, and polished surfaces are limited by microporosity.
Can AC1A be formed, bent or molded?
Sand and permanent-mold casting only; needs strong directional solidification with generous risers, chills and controlled pouring to fight hot tearing and interdendritic shrinkage — low pressure-tightness.
What is the maximum service temperature of AC1A?
AC1A is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AC1A-T6 and AC1A-F?
T6 is the default condition — standard high-strength condition for structural castings; pick it when maximum tensile/yield strength and hardness are required and ductility can be traded away. F: lowest cost condition for non-critical parts or blanks that will be heat treated later; strength is modest and the structure is cored. Yield strength is 250 MPa in T6 versus 95 MPa in F.
How much does AC1A cost?
AC1A is a premium-cost aluminum ($$$), cheaper than about 51% 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 H 5202 Aluminium alloy castings — JSA (2010)
- GB/T 1173 (ZL201/ZL201A) — SAC (2013)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (Aluminium casting alloys 201.0/204.0) — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
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.