Aluminum 6061 · temper · default condition
Aluminum 6061-T6
Properties of the T6 condition, compared with the other 6061 tempers.
Default choice: peak-strength general engineering temper for machined parts, frames, fixtures and structural extrusions.
What is 6061-T6?
6061-T6 is 6061 in the T6 temper — default choice: peak-strength general engineering temper for machined parts, frames, fixtures and structural extrusions. 6061-T6 has a yield strength of 276 MPa (40 ksi) and a tensile strength of 310 MPa (45 ksi) — stronger than 71% of aluminum grades. Elongation at break is 12% and the elastic modulus is 68.9 GPa (9.99 Msi). 6061-T6 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 60% of aluminum grades. It melts at 582°C (1,080 °F).
Advantages
- High electrical conductivity — 43 % IACS, better than 83% of aluminum grades
- Conducts heat well — 167 W/m·K (96.5 BTU/hr·ft·°F), better than 81% of aluminum grades
- High service temperature — 170°C (338 °F), better than 80% of aluminum grades
- Readily welded — 85/100, better than 79% of aluminum grades
6061-T6 properties
Typical room-temperature values for 6061-T6 — 18 properties are specific to this condition; the rest are grade-level values shared by every 6061 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
6061-T6 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 60% of aluminum grades. It melts at 582°C (1,080 °F).
Mechanical16
6061-T6 has a yield strength of 276 MPa (40 ksi) and a tensile strength of 310 MPa (45 ksi) — stronger than 71% of aluminum grades. Elongation at break is 12% and the elastic modulus is 68.9 GPa (9.99 Msi).
Thermal6
6061-T6 is rated for continuous service to 170°C (338 °F). It conducts heat at 167 W/m·K (96.5 BTU/hr·ft·°F), better than 81% of aluminum grades. Thermal expansion is 23.6 µm/m·K (13.1 µin/in·°F).
Electrical3
6061-T6 conducts electricity at 43 % IACS, better than 83% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 51% of aluminum grades.
Sustainability4
Producing a kilogram of 6061-T6 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 35%.
Manufacturability6
6061-T6's machinability is very good (70/100, better than 72% of aluminum grades); weldability excellent (85/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 6061 tempers and conditions
6061 is also supplied in 20 other conditions. The full side-by-side table is on the 6061 overview.
- T6DefaultDefault choice: peak-strength general engineering temper for machined parts, frames, fixtures and structural extrusions.276 MPa yield · 95 HB
- T94Peak-strength cold-finished temper for 6061 bar/wire: aged to T6 and then cold worked, delivering the highest 6061 strength level at low elongation and poor cold formability.414 MPa yield · 116 HB
- T89High-strength thermomechanical temper for 6061 rod/bar/wire: solution treated, cold worked, then artificially aged, giving roughly 15–20 % more strength than T6 with reduced ductility and formability.386 MPa yield · 110 HB
- T651The standard plate temper for precision machined parts and mould/jig plate: T6 strength with low residual stress and minimal warping.276 MPa yield · 95 HB
- T5Economical press-quenched-and-aged extrusions where near-T6 strength with less distortion is acceptable.240 MPa yield · 85 HB
- T4Choose when parts must be bent, drawn or roll-formed at medium strength and then optionally aged to T6.145 MPa yield · 65 HB
- As PrintedAs-built additively manufactured 6061 (often with grain-refining modifiers such as 6061-RAM2); anisotropic, hot-crack prone and normally heat treated before use.140 MPa yield · 60 HB
- OPick for maximum formability (deep drawing, tight bends) before subsequent solution treatment and ageing.55 MPa yield · 30 HB
Working with 6061-T6
Is 6061 easy to machine?
Machines very well in T6/T651 with polished-flute carbide, high speed and air/mist or flood coolant; annealed or T4 material is gummy and builds up on the edge.
Can 6061 be welded?
Readily GTAW/GMAW/FSW welded — use 4043 for crack resistance or 5356 for higher weld ductility/anodizing match; expect HAZ strength to drop to roughly T4 levels unless the part is re-solutionised and aged.
Can 6061 be formed, bent or molded?
Form, bend and draw in O or T4 and age afterwards; T6 tolerates only generous bend radii (≈4–6 t) and is prone to cracking on tight bends. Extrudes and forges easily at 375–500 °C.
What surface finishes work on 6061?
Excellent for clear, colour and Type III hard anodizing (expect a slight grey cast), chromate/Ti-Zr conversion coating, powder coat and paint; bright polishing is limited by second-phase particles, and electroless nickel or zincate-plus-electroplate is used for plating.
6061 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 – 0.8 | 0.6 |
| Feimpurity limit | ≤ 0.7 | 0.35 |
| Cu | 0.15 – 0.4 | 0.28 |
| Mn | ≤ 0.15 | 0.05 |
| Mgforms Mg2Si strengthening precipitates | 0.8 – 1.2 | 1 |
| Crgrain control, SCC resistance | 0.04 – 0.35 | 0.2 |
| Zn | ≤ 0.25 | 0.05 |
| Ti | ≤ 0.15 | 0.05 |
| Others (each)total 0.15 max | ≤ 0.05 | — |
| Alremainder, ~95.8–98.6 % | balance | — |
6061-T6 — frequently asked
What is 6061-T6 used for?
6061-T6 is typically used for general CNC machined parts, aerospace and structural brackets, hydraulic manifolds and valve bodies, machine frames and extruded structural profiles, robotics and automation components and tooling plate and jig fixtures. In short: the go-to general purpose; versatile.
What is the yield strength of 6061-T6?
6061-T6 has a typical yield strength of 276 MPa (40 ksi) and a tensile strength of 310 MPa (45 ksi) — stronger than 71% of aluminum grades. Strength varies by condition: see the 21 listed tempers.
Is 6061-T6 easy to machine?
Yes — machinability is rated very good (70/100, better than 72% of aluminum grades). Machines very well in T6/T651 with polished-flute carbide, high speed and air/mist or flood coolant; annealed or T4 material is gummy and builds up on the edge.
Can 6061-T6 be welded?
Yes — weldability is rated excellent (85/100). Readily GTAW/GMAW/FSW welded — use 4043 for crack resistance or 5356 for higher weld ductility/anodizing match; expect HAZ strength to drop to roughly T4 levels unless the part is re-solutionised and aged.
What surface finishes work on 6061-T6?
Excellent for clear, colour and Type III hard anodizing (expect a slight grey cast), chromate/Ti-Zr conversion coating, powder coat and paint; bright polishing is limited by second-phase particles, and electroless nickel or zincate-plus-electroplate is used for plating.
Can 6061-T6 be formed, bent or molded?
Form, bend and draw in O or T4 and age afterwards; T6 tolerates only generous bend radii (≈4–6 t) and is prone to cracking on tight bends. Extrudes and forges easily at 375–500 °C.
What is the maximum service temperature of 6061-T6?
6061-T6 is rated for continuous use to about 170°C (338 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 6061-T6 and 6061-O?
T6 is the default condition — default choice: peak-strength general engineering temper for machined parts, frames, fixtures and structural extrusions. O: pick for maximum formability (deep drawing, tight bends) before subsequent solution treatment and ageing. Yield strength is 276 MPa in T6 versus 55 MPa in O.
Can FabDigit make parts in 6061-T6?
Yes — 6061-T6 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASTM B209 / B209M — Aluminum and Aluminum-Alloy Sheet and Plate — ASTM International (2021)
- ASTM B221 — Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles and Tubes — ASTM International (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- MMPDS-17 — Metallic Materials Properties Development and Standardization — Battelle/FAA (2022)
- EN 573-3 / EN 485-2 — EN AW-6061 (AlMg1SiCu) — CEN (2019)
- 6061 alloy technical datasheets (Alcoa / Constellium / Kaiser) — producers (2023)
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.