Aluminum AC2B-T7
Temper
JIS AC2B
T7 = solution heat treated and overaged (stabilized)
Use where dimensional stability at elevated temperature matters more than peak strength.
Values for the T7 condition
Other AC2B tempers and conditions
AC2B is listed in 4 conditions; see the grade overview at AC2B.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
FDefault As fabricated | Default, lowest-cost condition for general non-critical sand or permanent-mold castings. | 110 | 180 | 2 | 70 HB | 27 % IACS |
Cooled from hot working and artificially aged | Cheap strength/stability bump without solution treatment; used to stabilize dimensions before machining. | 150 | 200 | 1.5 | 80 HB | 28 % IACS |
T7This page Solution heat treated and overaged (stabilized) | Use where dimensional stability at elevated temperature matters more than peak strength. | 165 | 230 | 2.5 | 82 HB | 30 % IACS |
Solution heat treated and artificially aged | Pick when maximum strength and hardness are needed from an AC2B casting; JIS minimum 240 MPa. | 200 | 270 | 2 | 95 HB | 29 % IACS |
What is AC2B-T7?
AC2B-T7 is AC2B in the T7 temper — use where dimensional stability at elevated temperature matters more than peak strength. AC2B-T7 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 58% of aluminum grades. Elongation at break is 2.5% and the elastic modulus is 74 GPa (10.7 Msi). AC2B-T7 has a density of 2.77 g/cm³ (0.1 lb/in³), heavier than 71% of aluminum grades. It melts at 516°C (961 °F). F is the default condition FabDigit quotes; T7 is available on request or by drawing note.
Advantages
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
Limitations
- Limited formability — 5/100, worse than 94% of aluminum grades
- Hard to polish — 40/100, worse than 91% of aluminum grades
- Limited ductility — 2.5%, worse than 83% of aluminum grades
- Poor heat conductor — 120 W/m·K (69.3 BTU/hr·ft·°F), worse than 80% of aluminum grades
AC2B-T7 properties
Typical room-temperature values for AC2B-T7; 21 are specific to this condition. Other listed values are AC2B reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
AC2B-T7 has a density of 2.77 g/cm³ (0.1 lb/in³), heavier than 71% of aluminum grades. It melts at 516°C (961 °F).
Mechanical13
AC2B-T7 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 58% of aluminum grades. Elongation at break is 2.5% and the elastic modulus is 74 GPa (10.7 Msi).
Thermal6
AC2B-T7 is rated for continuous service to 200°C (392 °F). It conducts heat at 120 W/m·K (69.3 BTU/hr·ft·°F), worse than 80% of aluminum grades. Thermal expansion is 21.5 µm/m·K (11.9 µin/in·°F).
Electrical3
AC2B-T7 conducts electricity at 30 % IACS, worse than 73% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (46/100), worse than 59% of aluminum grades.
Sustainability4
Producing a kilogram of AC2B-T7 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 85%.
Manufacturability8
AC2B-T7's machinability is good (68/100, better than 67% of aluminum grades); weldability fair (35/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with AC2B-T7
Is AC2B easy to machine?
Machines freely with carbide/PCD tooling; use high speed, generous coolant and sharp geometry — free Si is abrasive and porosity can smear.
Can AC2B be welded?
Cu content makes it hot-crack prone; repair-weld with 4043/4145 filler, preheat 150–200 °C and keep heat input low; post-weld T6 recovers strength.
Can AC2B be formed, bent or molded?
Casting alloy only — excellent fluidity for thin sand/permanent-mold sections; degas and grain-refine to control shrinkage porosity; no cold forming.
What surface finishes work on AC2B?
Do not use decorative anodizing (dark grey mottling from Si/Cu); prefer shot blast + chromate/conversion coat, powder coat or paint; impregnation often needed for pressure tightness.
AC2B 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 |
|---|---|---|
| Si | 5 – 7 | 6 |
| Cu | 2 – 4 | 3 |
| Mg | ≤ 0.5 | 0.15 |
| Znwider tolerance than AC2A | ≤ 1 | — |
| Fesecondary-ingot impurity | ≤ 1 | 0.7 |
| Mn | ≤ 0.5 | — |
| Ni | ≤ 0.35 | — |
| Tigrain refiner | ≤ 0.2 | — |
| Sn | ≤ 0.1 | — |
| Pb | ≤ 0.2 | — |
| Al | balance | — |
AC2B-T7 — frequently asked
What is AC2B-T7 used for?
AC2B-T7 is typically used for housings, brackets and general castings. In short: low-cost general casting alloy; wide composition tolerance; non-critical parts only.
What is the yield strength of AC2B-T7?
AC2B-T7 has a typical yield strength of 165 MPa (23.9 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 58% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is AC2B-T7 easy to machine?
Reasonably — machinability is rated good (68/100, better than 67% of aluminum grades). Machines freely with carbide/PCD tooling; use high speed, generous coolant and sharp geometry — free Si is abrasive and porosity can smear.
Can AC2B-T7 be welded?
With care — weldability is rated fair (35/100). Cu content makes it hot-crack prone; repair-weld with 4043/4145 filler, preheat 150–200 °C and keep heat input low; post-weld T6 recovers strength.
What surface finishes work on AC2B-T7?
Do not use decorative anodizing (dark grey mottling from Si/Cu); prefer shot blast + chromate/conversion coat, powder coat or paint; impregnation often needed for pressure tightness.
Can AC2B-T7 be formed, bent or molded?
Casting alloy only — excellent fluidity for thin sand/permanent-mold sections; degas and grain-refine to control shrinkage porosity; no cold forming.
What is the maximum service temperature of AC2B-T7?
AC2B-T7 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AC2B-F and AC2B-T6?
F is the default condition — default, lowest-cost condition for general non-critical sand or permanent-mold castings. T6: pick when maximum strength and hardness are needed from an AC2B casting; JIS minimum 240 MPa. Yield strength is 110 MPa in F versus 200 MPa in T6.
Sources
- JIS H 5202 Aluminium alloy castings — JSA (2010)
- ASTM B26/B26M Standard Specification for Aluminum-Alloy Sand Castings — ASTM (2018)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (319.0) — ASM International (1990)
- ASM Handbook Vol.15 — Casting — ASM International (2008)
- Aluminum Association Teal Sheets — casting alloy 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.