Aluminum AC4C-T5
Temper
JIS AC4C · ASTM 356.0
T5 = cooled from hot working and artificially aged
Low-distortion route: modest strength/hardness gain and stress relief without a solution treatment quench.
Values for the T5 condition
Other AC4C tempers and conditions
AC4C is listed in 5 conditions; see the grade overview at AC4C.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Cheapest condition for low-stress housings and covers where dimensional stability and strength demands are modest. | 85 | 165 | 5 | 55 HB | 41 % IACS |
T5This page Cooled from hot working and artificially aged | Low-distortion route: modest strength/hardness gain and stress relief without a solution treatment quench. | 125 | 185 | 4 | 65 HB | 42 % IACS |
T6Default Solution heat treated and artificially aged | Standard structural condition: best balance of strength, ductility and fatigue life for wheels, knuckles and pressure-tight housings. | 180 | 250 | 5 | 80 HB | 39 % IACS |
Solution heat treated and overaged (stabilized) | Overaged for dimensional stability, reduced residual stress and better toughness at elevated service temperature, at some loss of peak strength. | 195 | 230 | 5 | 70 HB | 42 % IACS |
T6 variant, underaged | Choose when maximum strength/hardness matters more than elongation, e.g. highly loaded permanent-mold or squeeze castings. | 225 | 280 | 3 | 90 HB | 38 % IACS |
What is AC4C-T5?
AC4C-T5 is AC4C in the T5 temper — low-distortion route: modest strength/hardness gain and stress relief without a solution treatment quench. AC4C-T5 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 185 MPa (26.8 ksi) — weaker than 75% of aluminum grades. Elongation at break is 4% and the elastic modulus is 72.4 GPa (10.5 Msi). AC4C-T5 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 557°C (1,035 °F). T6 is the default condition FabDigit quotes; T5 is available on request or by drawing note.
Advantages
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
- High electrical conductivity — 42 % IACS, better than 81% of aluminum grades
Limitations
- Low strength — 125 MPa (18.1 ksi), worse than 75% of aluminum grades
AC4C-T5 properties
Typical room-temperature values for AC4C-T5; 10 are specific to this condition. Other listed values are AC4C reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
AC4C-T5 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 557°C (1,035 °F).
Mechanical14
AC4C-T5 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 185 MPa (26.8 ksi) — weaker than 75% of aluminum grades. Elongation at break is 4% and the elastic modulus is 72.4 GPa (10.5 Msi).
Thermal6
AC4C-T5 is rated for continuous service to 175°C (347 °F). It conducts heat at 154 W/m·K (89 BTU/hr·ft·°F), better than 68% of aluminum grades. Thermal expansion is 21.5 µm/m·K (11.9 µin/in·°F).
Electrical3
AC4C-T5 conducts electricity at 42 % IACS, better than 81% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), better than 57% of aluminum grades.
Sustainability4
Producing a kilogram of AC4C-T5 takes about 175 MJ of energy and emits 11.5 kg of CO₂ — less than 92% of aluminum grades. Typical recycled content is 55%.
Manufacturability7
AC4C-T5's machinability is good (58/100, worse than 54% of aluminum grades); weldability very good (75/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AC4C-T5
Is AC4C easy to machine?
Machines cleanly with sharp positive-rake carbide or PCD tooling at high speed; the eutectic Si abrades HSS, so use flood coolant and expect shorter tool life than 6061.
Can AC4C be welded?
Readily TIG/MIG welded with ER4043 or ER4047 filler; weld zone loses T6 properties, so re-solution and re-age for full strength and avoid welding heavily gas-porous castings.
Can AC4C be formed, bent or molded?
Excellent fluidity and feeding for sand, gravity, low-pressure and squeeze casting; degas, Sr-modify and grain-refine, and keep Fe low to protect ductility.
What surface finishes work on AC4C?
Takes protective and hard-coat anodize (grey, non-decorative), chromate/Ti-Zr conversion coats, powder coat and paint; impregnation is common for pressure tightness before plating.
AC4C 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 |
|---|---|---|
| SiSr or Na modified for fine eutectic | 6.5 – 7.5 | 7 |
| MgMg2Si precipitation hardening | 0.2 – 0.45 | 0.32 |
| Fe≤0.20 for premium/A356.2 quality | ≤ 0.55 | 0.15 |
| Cu | ≤ 0.25 | 0.05 |
| Mn | ≤ 0.35 | 0.05 |
| Zn | ≤ 0.35 | 0.05 |
| Tigrain refinement with Al-Ti-B | ≤ 0.2 | 0.12 |
| Ni | ≤ 0.1 | — |
| Cr | ≤ 0.1 | — |
| Pb | ≤ 0.05 | — |
| Sn | ≤ 0.05 | — |
| Al | balance | — |
AC4C-T5 — frequently asked
What is AC4C-T5 used for?
AC4C-T5 is typically used for automotive wheels, structural chassis parts, aerospace castings and gearbox housings. In short: A356 equivalent casting alloy; pressure-tight structural castings; best all-round AC grade.
What is the yield strength of AC4C-T5?
AC4C-T5 has a typical yield strength of 125 MPa (18.1 ksi) and a tensile strength of 185 MPa (26.8 ksi) — weaker than 75% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is AC4C-T5 easy to machine?
Reasonably — machinability is rated good (58/100, worse than 54% of aluminum grades). Machines cleanly with sharp positive-rake carbide or PCD tooling at high speed; the eutectic Si abrades HSS, so use flood coolant and expect shorter tool life than 6061.
Can AC4C-T5 be welded?
Yes — weldability is rated very good (75/100). Readily TIG/MIG welded with ER4043 or ER4047 filler; weld zone loses T6 properties, so re-solution and re-age for full strength and avoid welding heavily gas-porous castings.
What surface finishes work on AC4C-T5?
Takes protective and hard-coat anodize (grey, non-decorative), chromate/Ti-Zr conversion coats, powder coat and paint; impregnation is common for pressure tightness before plating.
Can AC4C-T5 be formed, bent or molded?
Excellent fluidity and feeding for sand, gravity, low-pressure and squeeze casting; degas, Sr-modify and grain-refine, and keep Fe low to protect ductility.
What is the maximum service temperature of AC4C-T5?
AC4C-T5 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 AC4C-T6 and AC4C-F?
T6 is the default condition — standard structural condition: best balance of strength, ductility and fatigue life for wheels, knuckles and pressure-tight housings. F: cheapest condition for low-stress housings and covers where dimensional stability and strength demands are modest. Yield strength is 180 MPa in T6 versus 85 MPa in F.
Sources
- JIS H 5202 Aluminium Alloy Castings — JSA (2010)
- GB/T 1173 (ZL101) — SAC (2013)
- ASTM B26/B26M & B108 (A356.0) — ASTM (2018)
- EN 1706 (EN AC-42000 AlSi7Mg) — CEN (2020)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- Aluminum Association Teal Sheets / Alloy & Temper Registrations — The Aluminum Association (2015)
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.