Aluminum AC5A-T5
Temper
JIS AC5A
T5 = cooled from hot working and artificially aged
Simple ageing without solution treatment — dimensionally stable pistons where distortion from quenching must be avoided.
Values for the T5 condition
Other AC5A tempers and conditions
AC5A is listed in 4 conditions; see the grade overview at AC5A.
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 hot parts or as an intermediate state before machining and ageing. | 130 | 175 | 1 | 75 HB | 33 % IACS |
T5This page Cooled from hot working and artificially aged | Simple ageing without solution treatment — dimensionally stable pistons where distortion from quenching must be avoided. | 190 | 215 | 1 | 95 HB | 34 % IACS |
Solution heat treated and overaged (stabilized) | Overaged for maximum dimensional and thermal stability plus better ductility, at some loss of room-temperature strength. | 205 | 245 | 1.5 | 95 HB | 36 % IACS |
T6Default Solution heat treated and artificially aged | Standard peak-strength condition for highly loaded pistons, cylinder heads and hot structural castings. | 255 | 295 | 1 | 105 HB | 30 % IACS |
What is AC5A-T5?
AC5A-T5 is AC5A in the T5 temper — simple ageing without solution treatment — dimensionally stable pistons where distortion from quenching must be avoided. AC5A-T5 has a yield strength of 190 MPa (27.6 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 52% of aluminum grades. Elongation at break is 1% and the elastic modulus is 71 GPa (10.3 Msi). AC5A-T5 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 528°C (982 °F). T6 is the default condition FabDigit quotes; T5 is available on request or by drawing note.
Advantages
- High service temperature — 250°C (482 °F), better than 97% of aluminum grades
- Low embodied carbon — 10.5 kg CO₂/kg, better than 95% of aluminum grades
Limitations
- Needs corrosion protection — 30/100, worse than 98% of aluminum grades
- Limited ductility — 1%, worse than 95% of aluminum grades
- Limited formability — 5/100, worse than 94% of aluminum grades
- Low fracture toughness — 17 MPa·√m (15.5 ksi·√in), worse than 83% of aluminum grades
- Difficult to weld — 25/100, worse than 76% of aluminum grades
AC5A-T5 properties
Typical room-temperature values for AC5A-T5; 11 are specific to this condition. Other listed values are AC5A reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
AC5A-T5 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 528°C (982 °F).
Mechanical14
AC5A-T5 has a yield strength of 190 MPa (27.6 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 52% of aluminum grades. Elongation at break is 1% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
AC5A-T5 is rated for continuous service to 250°C (482 °F). It conducts heat at 135 W/m·K (78 BTU/hr·ft·°F), worse than 58% of aluminum grades. Thermal expansion is 22.5 µm/m·K (12.5 µin/in·°F).
Electrical3
AC5A-T5 conducts electricity at 34 % IACS, worse than 52% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), worse than 98% of aluminum grades.
Sustainability4
Producing a kilogram of AC5A-T5 takes about 150 MJ of energy and emits 10.5 kg of CO₂ — less than 97% of aluminum grades. Typical recycled content is 35%.
Manufacturability8
AC5A-T5's machinability is very good (70/100, better than 72% of aluminum grades); weldability poor (25/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AC5A-T5
Is AC5A easy to machine?
Machines very well with carbide tooling and high speeds; the Cu/Ni intermetallics give short chips and good finish, but they are abrasive so PCD is preferred for high-volume piston skirt turning.
Can AC5A be welded?
Poor fusion weldability — high Cu content makes it hot-crack prone; repair only with 4145/2319 filler, preheat 150–200 °C and re-age afterwards.
Can AC5A be formed, bent or molded?
Gravity die (permanent mold) or sand cast with good feeding and chills; narrow freezing range is not favorable — expect hot tearing at section changes and design generous fillets.
What surface finishes work on AC5A?
Hard (Type III) anodize on crowns/ring grooves for wear and heat; decorative anodizing is dark and blotchy, so painting, Ni or ferrous ring-carrier inserts are used where appearance or corrosion matters.
AC5A 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 |
|---|---|---|
| Cu | 3.5 – 4.5 | 4 |
| Niprovides elevated-temperature strength | 1.7 – 2.3 | 2 |
| Mg | 1.2 – 1.8 | 1.5 |
| Si | ≤ 0.6 | 0.3 |
| Fe | ≤ 0.8 | 0.4 |
| Mn | ≤ 0.35 | — |
| Zn | ≤ 0.15 | — |
| Tigrain refiner | ≤ 0.2 | — |
| Cr | ≤ 0.15 | — |
| Sn | ≤ 0.05 | — |
| Pb | ≤ 0.05 | — |
| Al | balance | — |
AC5A-T5 — frequently asked
What is AC5A-T5 used for?
AC5A-T5 is typically used for engine pistons, cylinder heads and high-temperature components. In short: highest service temperature, 220 °C; classic piston casting alloy; low ductility and corrosion resistance.
What is the yield strength of AC5A-T5?
AC5A-T5 has a typical yield strength of 190 MPa (27.6 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 52% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is AC5A-T5 easy to machine?
Yes — machinability is rated very good (70/100, better than 72% of aluminum grades). Machines very well with carbide tooling and high speeds; the Cu/Ni intermetallics give short chips and good finish, but they are abrasive so PCD is preferred for high-volume piston skirt turning.
Can AC5A-T5 be welded?
Not readily — weldability is rated poor (25/100). Poor fusion weldability — high Cu content makes it hot-crack prone; repair only with 4145/2319 filler, preheat 150–200 °C and re-age afterwards.
What surface finishes work on AC5A-T5?
Hard (Type III) anodize on crowns/ring grooves for wear and heat; decorative anodizing is dark and blotchy, so painting, Ni or ferrous ring-carrier inserts are used where appearance or corrosion matters.
Can AC5A-T5 be formed, bent or molded?
Gravity die (permanent mold) or sand cast with good feeding and chills; narrow freezing range is not favorable — expect hot tearing at section changes and design generous fillets.
What is the maximum service temperature of AC5A-T5?
AC5A-T5 is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AC5A-T6 and AC5A-F?
T6 is the default condition — standard peak-strength condition for highly loaded pistons, cylinder heads and hot structural castings. F: lowest-cost condition for non-critical hot parts or as an intermediate state before machining and ageing. Yield strength is 255 MPa in T6 versus 130 MPa in F.
Sources
- JIS H 5202 Aluminium alloy castings — JSA (2010)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys (Alloy 242.0) — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASTM B26/B26M and B108/B108M (242.0 castings) — ASTM (2018)
- Aluminum Association Registration Record (Pink Sheets) — cast alloy 242.0 — The Aluminum Association (2018)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.