Aluminum 6261-T4
Temper
AA 6261 · UNS A96261 · EN AlMg1SiCuMn
T4 = solution heat treated and naturally aged
Choose when bending, stretch-forming or roll-forming is needed after heat treatment, with a later T6-type ageing to recover strength.
Values for the T4 condition
Other 6261 tempers and conditions
6261 is listed in 9 conditions; see the grade overview at 6261.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for maximum formability before a later solution treat and age; not a structural condition. | 65 | 130 | 25 | 32 HB | 49 % IACS |
Slightly strain hardened | Soft mill/extruded condition with incidental work hardening from handling or straightening; used where the part will be formed then heat treated. | 85 | 150 | 20 | 38 HB | 48 % IACS |
T4This page Solution heat treated and naturally aged | Choose when bending, stretch-forming or roll-forming is needed after heat treatment, with a later T6-type ageing to recover strength. | 140 | 250 | 18 | 68 HB | 39 % IACS |
Solution treated, naturally aged, stress-relieved by stretching | Straight, low-residual-stress bar/tube in the formable T4 state for later forming and ageing. | 140 | 245 | 17 | 67 HB | 40 % IACS |
Cooled from hot working and artificially aged | Economical press-quenched temper for thin-wall profiles where full T6 strength and straightness after solution treatment are not required. | 250 | 290 | 8 | 90 HB | 44 % IACS |
T6, stress relieved by stretching | Specify when machined parts must stay dimensionally stable after heavy stock removal from plate or heavy extrusions. | 295 | 325 | 10 | 98 HB | 43 % IACS |
Solution treated, stretch stress-relieved, artificially aged | Precision extruded bar/profile for machined structural parts where distortion must be minimised. | 295 | 325 | 10 | 98 HB | 43 % IACS |
T6Default Solution heat treated and artificially aged | Standard structural condition for 6261 — the reason to specify this alloy over 6061/6082; use for load-bearing tubes, scaffolding and framing. | 300 | 330 | 10 | 100 HB | 43 % IACS |
T6 with improved mechanical properties | European extruder temper giving slightly higher guaranteed proof strength than T6 with controlled ageing; used for scaffolding and access towers. | 315 | 345 | 9 | 105 HB | 43 % IACS |
What is 6261-T4?
6261-T4 is 6261 in the T4 temper — choose when bending, stretch-forming or roll-forming is needed after heat treatment, with a later T6-type ageing to recover strength. 6261-T4 has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 70% of aluminum grades. Elongation at break is 18% and the elastic modulus is 70 GPa (10.2 Msi). 6261-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 585°C (1,085 °F). T6 is the default condition FabDigit quotes; T4 is available on request or by drawing note.
Advantages
- Ductile — tolerates forming and impact — 18%, better than 86% of aluminum grades
- Forms and bends easily — 68/100, better than 81% of aluminum grades
Limitations
- Limited service temperature — 100°C (212 °F), worse than 91% of aluminum grades
- Difficult to machine — 42/100, worse than 77% of aluminum grades
6261-T4 properties
Typical room-temperature values for 6261-T4; 15 are specific to this condition. Other listed values are 6261 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
6261-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 585°C (1,085 °F).
Mechanical13
6261-T4 has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 70% of aluminum grades. Elongation at break is 18% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal6
6261-T4 is rated for continuous service to 100°C (212 °F). It conducts heat at 155 W/m·K (89.6 BTU/hr·ft·°F), better than 71% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
6261-T4 conducts electricity at 39 % IACS, better than 65% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), better than 57% of aluminum grades.
Sustainability4
Producing a kilogram of 6261-T4 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 35%.
Manufacturability8
6261-T4's machinability is fair (42/100, worse than 77% of aluminum grades); weldability very good (72/100); formability good (68/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 6261-T4
Is 6261 easy to machine?
Machines like 6061-T6: high speeds, polished-flute carbide, 3-flute cutters and coolant/lubricant to avoid built-up edge; gummy in O/T4.
Can 6261 be welded?
Readily GMAW/GTAW welded with ER4043 (crack resistance) or ER5356 (strength/anodizing match); expect HAZ strength down toward T4 levels unless post-weld solution treat and age.
Can 6261 be formed, bent or molded?
Extrudes and roll-forms well in O/T4; in T6 keep bend radii ≥3–4 t and avoid tight reverse bends — springback is high.
What surface finishes work on 6261?
Anodizes well (clear and hard coat) though the Cu content can darken clear films slightly; also takes chromate/anodic pretreat plus powder coat, and polishes to a satin finish.
6261 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 | 0.4 – 0.7 | 0.55 |
| Feimpurity limit | ≤ 0.4 | 0.2 |
| Curaises strength, slightly lowers corrosion margin | 0.15 – 0.4 | 0.27 |
| Mngrain/recrystallisation control | 0.2 – 0.35 | 0.28 |
| Mg | 0.7 – 1 | 0.85 |
| Cr | ≤ 0.1 | — |
| Zn | ≤ 0.2 | — |
| Ti | ≤ 0.1 | — |
| Others (each)0.15 % total | ≤ 0.05 | — |
| Al | balance | — |
6261-T4 — frequently asked
What is 6261-T4 used for?
6261-T4 is typically used for marine structural sections, transport frames and structural extrusions. In short: stronger than 6061-T6; weldable structural extrusion; marine and transport 6000 series.
What is the yield strength of 6261-T4?
6261-T4 has a typical yield strength of 140 MPa (20.3 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 70% of aluminum grades. Strength varies by condition: see the 9 listed tempers.
Is 6261-T4 easy to machine?
Not especially — machinability is rated fair (42/100, worse than 77% of aluminum grades). Machines like 6061-T6: high speeds, polished-flute carbide, 3-flute cutters and coolant/lubricant to avoid built-up edge; gummy in O/T4.
Can 6261-T4 be welded?
Yes — weldability is rated very good (72/100). Readily GMAW/GTAW welded with ER4043 (crack resistance) or ER5356 (strength/anodizing match); expect HAZ strength down toward T4 levels unless post-weld solution treat and age.
What surface finishes work on 6261-T4?
Anodizes well (clear and hard coat) though the Cu content can darken clear films slightly; also takes chromate/anodic pretreat plus powder coat, and polishes to a satin finish.
Can 6261-T4 be formed, bent or molded?
Extrudes and roll-forms well in O/T4; in T6 keep bend radii ≥3–4 t and avoid tight reverse bends — springback is high.
What is the maximum service temperature of 6261-T4?
6261-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 6261-T6 and 6261-O?
T6 is the default condition — standard structural condition for 6261 — the reason to specify this alloy over 6061/6082; use for load-bearing tubes, scaffolding and framing. O: pick for maximum formability before a later solution treat and age; not a structural condition. Yield strength is 300 MPa in T6 versus 65 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- EN 755-2 Aluminium and aluminium alloys — Extruded rod/bar, tube and profiles — Mechanical properties — CEN (2016)
- EN 573-3 Chemical composition of wrought aluminium products — CEN (2019)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B: Corrosion — Materials — ASM International (2005)
- Extruded 6000-series structural profile datasheets (scaffolding/transport tempers T5/T6/T66) — European extruders (2022)
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.