Aluminum 520.0-T4
Temper · default condition
AA 520.0 · UNS A05200 · BS LM10
T4 = solution heat treated and naturally aged
The only commercially supplied condition — long solution treatment (~420 °C, 12–18 h) then quench and natural age, giving maximum strength plus ductility.
Values for the T4 condition
Other 520.0 tempers and conditions
520.0 is listed in 2 conditions; see the grade overview at 520.0.
- F
- T4
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Rarely sold; as-cast structure has coarse Al8Mg5 network giving low ductility — use only for non-structural or trial castings before solution treatment. | 110 | 180 | 3 | 60 HB | 19 % IACS |
T4DefaultThis page Solution heat treated and naturally aged | The only commercially supplied condition — long solution treatment (~420 °C, 12–18 h) then quench and natural age, giving maximum strength plus ductility. | 180 | 330 | 16 | 75 HB | 21 % IACS |
What is 520.0-T4?
520.0-T4 is 520.0 in the T4 temper — the only commercially supplied condition — long solution treatment (~420 °C, 12–18 h) then quench and natural age, giving maximum strength plus ductility. 520.0-T4 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 54% of aluminum grades. Elongation at break is 16% and the elastic modulus is 68 GPa (9.86 Msi). 520.0-T4 has a density of 2.57 g/cm³ (0.0928 lb/in³), lighter than 99% of aluminum grades. It melts at 449°C (840 °F).
Advantages
- Easy to machine — 90/100, better than 98% of aluminum grades
- Good corrosion resistance — 78/100, better than 94% of aluminum grades
- Polishes to a fine finish — 80/100, better than 93% of aluminum grades
- Ductile — tolerates forming and impact — 16%, better than 84% of aluminum grades
Limitations
- Poor heat conductor — 87 W/m·K (50.3 BTU/hr·ft·°F), worse than 100% of aluminum grades
- Low electrical conductivity — 21 % IACS, worse than 99% of aluminum grades
- Limited service temperature — 100°C (212 °F), worse than 91% of aluminum grades
- Difficult to weld — 25/100, worse than 76% of aluminum grades
520.0-T4 properties
Typical room-temperature values for 520.0-T4; 11 are specific to this condition. Other listed values are 520.0 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
520.0-T4 has a density of 2.57 g/cm³ (0.0928 lb/in³), lighter than 99% of aluminum grades. It melts at 449°C (840 °F).
Mechanical11
520.0-T4 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 54% of aluminum grades. Elongation at break is 16% and the elastic modulus is 68 GPa (9.86 Msi).
Thermal6
520.0-T4 is rated for continuous service to 100°C (212 °F). It conducts heat at 87 W/m·K (50.3 BTU/hr·ft·°F), worse than 100% of aluminum grades. Thermal expansion is 25 µm/m·K (13.9 µin/in·°F).
Electrical3
520.0-T4 conducts electricity at 21 % IACS, worse than 99% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is very good (78/100), better than 94% of aluminum grades.
Sustainability4
Producing a kilogram of 520.0-T4 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability7
520.0-T4's machinability is excellent (90/100, better than 98% of aluminum grades); weldability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 520.0-T4
Is 520.0 easy to machine?
Machines better than any other cast aluminium alloy — long clean chips, excellent surface finish; use sharp high-rake carbide/HSS tooling, high speeds, moderate feed, light lubricant.
Can 520.0 be welded?
Poor: use 5356 (Al-5Mg) filler under argon TIG/MIG with tight heat control; welds are hot-crack sensitive and the T4 properties in the HAZ are lost unless the part is re-solution-treated.
Can 520.0 be formed, bent or molded?
Sand casting only — very low fluidity, strong hot-tear tendency and violent Mg oxidation; requires protective flux/cover gas (SF6-free cover), sulphur-inhibited moulding sand, generous risering and a long 420 °C solution soak followed by quench and ≥10 days natural ageing.
What surface finishes work on 520.0?
Takes bright polishing and clear sulphuric anodizing very well thanks to its low silicon content; chromate/chrome-free conversion coatings and paint adhere readily, and no plating undercoat is normally needed for marine service.
520.0 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 |
|---|---|---|
| Mgprimary strengthening element | 9.5 – 10.6 | 10 |
| Si | ≤ 0.25 | — |
| Fe | ≤ 0.3 | — |
| Cu | ≤ 0.25 | — |
| Mn | ≤ 0.15 | — |
| Zn | ≤ 0.15 | — |
| Tigrain refiner | ≤ 0.25 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
520.0-T4 — frequently asked
What is 520.0-T4 used for?
520.0-T4 is typically used for aircraft fittings, food processing equipment, marine hardware, instrument housings and hand tools. In short: best-machining cast aluminium; high strength and 16% elongation; very poor castability.
What is the yield strength of 520.0-T4?
520.0-T4 has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 330 MPa (47.9 ksi) — weaker than 54% of aluminum grades. Strength varies by condition: see the 2 listed tempers.
Is 520.0-T4 easy to machine?
Yes — machinability is rated excellent (90/100, better than 98% of aluminum grades). Machines better than any other cast aluminium alloy — long clean chips, excellent surface finish; use sharp high-rake carbide/HSS tooling, high speeds, moderate feed, light lubricant.
Can 520.0-T4 be welded?
Not readily — weldability is rated poor (25/100). Poor: use 5356 (Al-5Mg) filler under argon TIG/MIG with tight heat control; welds are hot-crack sensitive and the T4 properties in the HAZ are lost unless the part is re-solution-treated.
What surface finishes work on 520.0-T4?
Takes bright polishing and clear sulphuric anodizing very well thanks to its low silicon content; chromate/chrome-free conversion coatings and paint adhere readily, and no plating undercoat is normally needed for marine service.
Can 520.0-T4 be formed, bent or molded?
Sand casting only — very low fluidity, strong hot-tear tendency and violent Mg oxidation; requires protective flux/cover gas (SF6-free cover), sulphur-inhibited moulding sand, generous risering and a long 420 °C solution soak followed by quench and ≥10 days natural ageing.
What is the maximum service temperature of 520.0-T4?
520.0-T4 is rated for continuous use to about 100°C (212 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 520.0-T4 and 520.0-F?
T4 is the default condition — the only commercially supplied condition — long solution treatment (~420 °C, 12–18 h) then quench and natural age, giving maximum strength plus ductility. F: rarely sold; as-cast structure has coarse Al8Mg5 network giving low ductility — use only for non-structural or trial castings before solution treatment. Yield strength is 180 MPa in T4 versus 110 MPa in F.
Sources
- ASTM B26/B26M — Aluminum-Alloy Sand Castings — ASTM International (2018)
- Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot ('Pink Sheets') — The Aluminum Association (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- GB/T 1173 (ZL301 Al-Mg10) — SAC (2013)
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.