Aluminum 6205-T4
Temper
AA 6205 · UNS A96205
T4 = solution heat treated and naturally aged
Use when tubes must be mitred, bent or hydroformed after heat treatment and then artificially aged to T6.
Values for the T4 condition
Other 6205 tempers and conditions
6205 is listed in 5 conditions; see the grade overview at 6205.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for maximum formability (bending, tube necking, deep drawing) before re-solution treating and aging. | 55 | 115 | 28 | 30 HB | 50 % IACS |
T4This page Solution heat treated and naturally aged | Use when tubes must be mitred, bent or hydroformed after heat treatment and then artificially aged to T6. | 130 | 240 | 22 | 62 HB | 41 % IACS |
Cooled from hot working and naturally aged | Lowest-cost as-extruded condition; use when moderate strength plus some remaining bendability is enough. | 152 | 262 | 19 | 65 HB | 42 % IACS |
T5Default Cooled from hot working and artificially aged | Standard stocked extrusion temper: near-T6 strength without a separate solution treatment, so straight thin-wall tube stays dimensionally stable. | 290 | 310 | 11 | 95 HB | 44 % IACS |
Solution heat treated and artificially aged | Highest-strength condition, used for butted bicycle frame tubing and structural parts that are welded then re-heat-treated. | 300 | 330 | 12 | 100 HB | 43 % IACS |
What is 6205-T4?
6205-T4 is 6205 in the T4 temper — use when tubes must be mitred, bent or hydroformed after heat treatment and then artificially aged to T6. 6205-T4 has a yield strength of 130 MPa (18.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 73% of aluminum grades. Elongation at break is 22% and the elastic modulus is 69 GPa (10 Msi). 6205-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 607°C (1,125 °F). T5 is the default condition FabDigit quotes; T4 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 22%, better than 91% of aluminum grades
- Polishes to a fine finish — 70/100, better than 87% of aluminum grades
- Forms and bends easily — 65/100, better than 80% of aluminum grades
- High electrical conductivity — 41 % IACS, better than 78% of aluminum grades
- Conducts heat well — 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades
Limitations
- Difficult to machine — 40/100, worse than 81% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
6205-T4 properties
Typical room-temperature values for 6205-T4; 10 are specific to this condition. Other listed values are 6205 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
6205-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 607°C (1,125 °F).
Mechanical12
6205-T4 has a yield strength of 130 MPa (18.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 73% of aluminum grades. Elongation at break is 22% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
6205-T4 is rated for continuous service to 120°C (248 °F). It conducts heat at 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
6205-T4 conducts electricity at 41 % IACS, better than 78% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (68/100), better than 75% of aluminum grades.
Sustainability4
Producing a kilogram of 6205-T4 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 30%.
Manufacturability8
6205-T4's machinability is fair (40/100, worse than 81% of aluminum grades); weldability very good (72/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 6205-T4
Is 6205 easy to machine?
Machines like 6061-T6 in T5/T6: sharp polished-flute carbide tools, high surface speed and flood/mist coolant to stop built-up edge; gummy and burr-prone in O/T4.
Can 6205 be welded?
Readily GTAW/GMAW welded with 4043 (or 5356 for anodized colour match); HAZ drops to roughly T4-level strength unless the part is re-solution-treated and aged.
Can 6205 be formed, bent or molded?
Extrudes well in thin, complex thin-wall sections; bend and butt tubes in O or T4 and age afterwards — cold bending in T5/T6 needs generous radii to avoid cracking.
What surface finishes work on 6205?
Excellent clear and colour anodizing with clean thin-wall surfaces; also takes chromate/chrome-free conversion coating, powder coat and mechanical polish.
6205 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 | 0.6 – 0.9 | 0.75 |
| Feimpurity limit | ≤ 0.7 | 0.25 |
| Cu | ≤ 0.2 | 0.05 |
| Mntight Mn limit aids extrudability/anodizing | ≤ 0.1 | 0.03 |
| Mg | 0.4 – 0.6 | 0.5 |
| Cr | 0.05 – 0.15 | 0.1 |
| Zn | ≤ 0.25 | 0.05 |
| Zrgrain-structure control, distinguishing addition | 0.05 – 0.15 | 0.1 |
| Ti | ≤ 0.15 | 0.02 |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
6205-T4 — frequently asked
What is 6205-T4 used for?
6205-T4 is typically used for bicycle frame tubing, sporting goods and structural extrusions. In short: higher-strength 6000-series tube alloy; thin-wall extrusion grade; clean anodizing surface.
What is the yield strength of 6205-T4?
6205-T4 has a typical yield strength of 130 MPa (18.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 73% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is 6205-T4 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 81% of aluminum grades). Machines like 6061-T6 in T5/T6: sharp polished-flute carbide tools, high surface speed and flood/mist coolant to stop built-up edge; gummy and burr-prone in O/T4.
Can 6205-T4 be welded?
Yes — weldability is rated very good (72/100). Readily GTAW/GMAW welded with 4043 (or 5356 for anodized colour match); HAZ drops to roughly T4-level strength unless the part is re-solution-treated and aged.
What surface finishes work on 6205-T4?
Excellent clear and colour anodizing with clean thin-wall surfaces; also takes chromate/chrome-free conversion coating, powder coat and mechanical polish.
Can 6205-T4 be formed, bent or molded?
Extrudes well in thin, complex thin-wall sections; bend and butt tubes in O or T4 and age afterwards — cold bending in T5/T6 needs generous radii to avoid cracking.
What is the maximum service temperature of 6205-T4?
6205-T4 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 6205-T5 and 6205-O?
T5 is the default condition — standard stocked extrusion temper: near-T6 strength without a separate solution treatment, so straight thin-wall tube stays dimensionally stable. O: pick for maximum formability (bending, tube necking, deep drawing) before re-solution treating and aging. Yield strength is 290 MPa in T5 versus 55 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASTM B221 — Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes — ASTM International (2021)
- Aluminum Standards and Data — The Aluminum Association (2017)
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.