Aluminum EN AC-21200-T7
Temper
EN AC-21200
T7 = solution heat treated and overaged (stabilized)
Overaged temper: slightly below peak strength but dimensionally stable and markedly less sensitive to intergranular/stress-corrosion attack — the choice for machined precision and long-life aerospace castings.
Values for the T7 condition
Other EN AC-21200 tempers and conditions
EN AC-21200 is listed in 4 conditions; see the grade overview at EN AC-21200.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Rarely used shipping condition: as-cast strength is low and unstable; normally an intermediate state before solution treatment. | 110 | 190 | 5 | 60 HB | 38 % IACS |
T4Default Solution heat treated and naturally aged | Standard supply condition: highest ductility and fracture toughness at high strength — choose for aerospace/structural castings that see impact or damage-tolerance requirements. | 210 | 320 | 7 | 95 HB | 31 % IACS |
T7This page Solution heat treated and overaged (stabilized) | Overaged temper: slightly below peak strength but dimensionally stable and markedly less sensitive to intergranular/stress-corrosion attack — the choice for machined precision and long-life aerospace castings. | 260 | 330 | 4 | 105 HB | 38 % IACS |
Solution heat treated and artificially aged | Peak-aged condition for maximum yield strength and hardness where ductility and stress-corrosion resistance are less critical. | 320 | 390 | 4 | 125 HB | 35 % IACS |
What is EN AC-21200-T7?
EN AC-21200-T7 is EN AC-21200 in the T7 temper — overaged temper: slightly below peak strength but dimensionally stable and markedly less sensitive to intergranular/stress-corrosion attack — the choice for machined precision and long-life aerospace castings. EN AC-21200-T7 has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 330 MPa (47.9 ksi) — stronger than 68% of aluminum grades. Elongation at break is 4% and the elastic modulus is 72 GPa (10.4 Msi). EN AC-21200-T7 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 545°C (1,013 °F). T4 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
- Easy to machine — 78/100, better than 89% of aluminum grades
Limitations
- Difficult to weld — 25/100, worse than 76% of aluminum grades
EN AC-21200-T7 properties
Typical room-temperature values for EN AC-21200-T7; 38 are specific to this condition. Other listed values are EN AC-21200 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
EN AC-21200-T7 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 545°C (1,013 °F).
Mechanical12
EN AC-21200-T7 has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 330 MPa (47.9 ksi) — stronger than 68% of aluminum grades. Elongation at break is 4% and the elastic modulus is 72 GPa (10.4 Msi).
Thermal6
EN AC-21200-T7 is rated for continuous service to 200°C (392 °F). It conducts heat at 150 W/m·K (86.7 BTU/hr·ft·°F), better than 58% of aluminum grades. Thermal expansion is 22.5 µm/m·K (12.5 µin/in·°F).
Electrical3
EN AC-21200-T7 conducts electricity at 38 % IACS, better than 61% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (42/100), worse than 69% of aluminum grades.
Sustainability4
Producing a kilogram of EN AC-21200-T7 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
EN AC-21200-T7's machinability is very good (78/100, better than 89% of aluminum grades); weldability poor (25/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with EN AC-21200-T7
Is EN AC-21200 easy to machine?
Machines very well in T4/T7 with sharp carbide tooling, high speeds and flood coolant; chips are short and surface finish is excellent.
Can EN AC-21200 be welded?
Poor fusion weldability — high hot-tearing risk; repair welding only with 2319/4145-type filler under qualified procedure followed by re-solution treatment.
Can EN AC-21200 be formed, bent or molded?
Difficult casting alloy: long freezing range, hot tearing and shrink porosity demand chills, generous risers, clean low-Fe charge and tight solution treatment (~525–530 °C) with rapid quench.
What surface finishes work on EN AC-21200?
Chromate/chemical conversion coating plus primer is standard; sulfuric or chromic anodize is possible but films are darker and less protective than on Al-Si-Mg alloys.
EN AC-21200 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 |
|---|---|---|
| Cuprincipal strengthening element | 4.2 – 5 | 4.6 |
| Mn | 0.2 – 0.5 | 0.35 |
| Mgboosts age-hardening response | 0.15 – 0.35 | 0.25 |
| Tigrain refinement | 0.15 – 0.3 | 0.22 |
| Siimpurity limit | ≤ 0.15 | — |
| Fekept low for toughness | ≤ 0.15 | — |
| Znimpurity limit | ≤ 0.1 | — |
| Niimpurity limit | ≤ 0.05 | — |
| Others (each)total ≤ 0.15 | ≤ 0.05 | — |
| Al | balance | — |
EN AC-21200-T7 — frequently asked
What is EN AC-21200-T7 used for?
EN AC-21200-T7 is typically used for aerospace structural parts, precision machined castings and engine brackets. In short: heat-treatable Al-Cu casting alloy; machines cleanly in T4/T7; low weldability.
What is the yield strength of EN AC-21200-T7?
EN AC-21200-T7 has a typical yield strength of 260 MPa (37.7 ksi) and a tensile strength of 330 MPa (47.9 ksi) — stronger than 68% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is EN AC-21200-T7 easy to machine?
Yes — machinability is rated very good (78/100, better than 89% of aluminum grades). Machines very well in T4/T7 with sharp carbide tooling, high speeds and flood coolant; chips are short and surface finish is excellent.
Can EN AC-21200-T7 be welded?
Not readily — weldability is rated poor (25/100). Poor fusion weldability — high hot-tearing risk; repair welding only with 2319/4145-type filler under qualified procedure followed by re-solution treatment.
What surface finishes work on EN AC-21200-T7?
Chromate/chemical conversion coating plus primer is standard; sulfuric or chromic anodize is possible but films are darker and less protective than on Al-Si-Mg alloys.
Can EN AC-21200-T7 be formed, bent or molded?
Difficult casting alloy: long freezing range, hot tearing and shrink porosity demand chills, generous risers, clean low-Fe charge and tight solution treatment (~525–530 °C) with rapid quench.
What is the maximum service temperature of EN AC-21200-T7?
EN AC-21200-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 EN AC-21200-T4 and EN AC-21200-T6?
T4 is the default condition — standard supply condition: highest ductility and fracture toughness at high strength — choose for aerospace/structural castings that see impact or damage-tolerance requirements. T6: peak-aged condition for maximum yield strength and hardness where ductility and stress-corrosion resistance are less critical. Yield strength is 210 MPa in T4 versus 320 MPa in T6.
Sources
- EN 1706 — Aluminium and aluminium alloys: castings, chemical composition and mechanical properties — CEN (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (206.0/A206.0 data) — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASTM B26/B26M — Aluminum-Alloy Sand Castings — ASTM (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.