Aluminum 6066-T451
Temper
AA 6066 · UNS A96066 · EN AW-6066, AW 6066
T451 = t4, stress relieved by stretching
T4 with a controlled stretch to relieve residual stress — pick for flat, low-distortion machining stock in the naturally aged condition.
Values for the T451 condition
Other 6066 tempers and conditions
6066 is listed in 11 conditions; see the grade overview at 6066.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for severe forming or machining of complex blanks before solution treating to T6. | 83 | 150 | 18 | 43 HB | 43 % IACS |
Solution heat treated and naturally aged by the user | Same metallurgy as T4 but heat treated by the fabricator after forming; slightly lower guaranteed properties. | 200 | 355 | 16 | 88 HB | 37 % IACS |
Solution heat treated and naturally aged | Medium-strength, more ductile condition for bending/forming of extrusions that will later be aged to T6 or used as-is. | 205 | 360 | 18 | 90 HB | 37 % IACS |
T451This page T4, stress relieved by stretching | T4 with a controlled stretch to relieve residual stress — pick for flat, low-distortion machining stock in the naturally aged condition. | 205 | 360 | 17 | 90 HB | 37 % IACS |
T4, stress relieved by stretching, no further straightening | Extruded T4 stress-relieved product supplied without post-stretch straightening; used where minor bow is acceptable. | 205 | 360 | 17 | 90 HB | 37 % IACS |
T4, stress relieved by stretching with minor straightening | Same as T4510 but minor straightening is permitted for tighter straightness tolerances on long extrusions. | 205 | 360 | 17 | 90 HB | 37 % IACS |
T6, heat treated by the user | Re-heat-treated to T6-level strength after forming or welding by the fabricator, when incoming material was O/F/T4. | 350 | 390 | 11 | 118 HB | 40 % IACS |
Solution heat treated and artificially aged | Standard peak-strength condition for structural extrusions, forgings and machined hydraulic/mechanical parts needing more strength than 6061-T6. | 359 | 395 | 12 | 120 HB | 40 % IACS |
T6, stress relieved by stretching | T6 stress-relieved stock for precision machined parts where distortion after material removal must be minimised. | 359 | 395 | 12 | 120 HB | 40 % IACS |
T6, stress relieved by stretching, no further straightening | Most common stress-relieved extrusion temper for long T6 profiles machined all over. | 359 | 395 | 12 | 120 HB | 40 % IACS |
T6, stress relieved by stretching, minor straightening | T6510 with limited straightening allowed — choose for tight straightness on bar and complex profiles. | 359 | 395 | 12 | 120 HB | 40 % IACS |
What is 6066-T451?
6066-T451 is 6066 in the T451 temper — t4 with a controlled stretch to relieve residual stress — pick for flat, low-distortion machining stock in the naturally aged condition. 6066-T451 has a yield strength of 205 MPa (29.7 ksi) and a tensile strength of 360 MPa (52.2 ksi) — stronger than 54% of aluminum grades. Elongation at break is 17% and the elastic modulus is 69 GPa (10 Msi). 6066-T451 has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 563°C (1,045 °F).
Advantages
- Ductile — tolerates forming and impact — 17%, better than 85% of aluminum grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
6066-T451 properties
Typical room-temperature values for 6066-T451; 22 are specific to this condition. Other listed values are 6066 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
6066-T451 has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 563°C (1,045 °F).
Mechanical11
6066-T451 has a yield strength of 205 MPa (29.7 ksi) and a tensile strength of 360 MPa (52.2 ksi) — stronger than 54% of aluminum grades. Elongation at break is 17% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
6066-T451 is rated for continuous service to 120°C (248 °F). It conducts heat at 140 W/m·K (80.9 BTU/hr·ft·°F), worse than 52% of aluminum grades. Thermal expansion is 23.2 µm/m·K (12.9 µin/in·°F).
Electrical3
6066-T451 conducts electricity at 37 % IACS, better than 58% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 56% of aluminum grades.
Sustainability4
Producing a kilogram of 6066-T451 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 30%.
Manufacturability6
6066-T451's machinability is good (62/100, better than 55% of aluminum grades); weldability fair (40/100); formability fair (52/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 6066-T451
Is 6066 easy to machine?
One of the better-machining 6000-series alloys thanks to Cu and Mn — sharp polished-flute carbide tools, high speed, chip-clearing coolant; T6/T651 gives cleaner chips than T4.
Can 6066 be welded?
Arc welding is discouraged (Cu-bearing, hot-crack and IGC prone); if required use 4043/4145 filler, low heat input and re-heat-treat plus age, expecting a weak HAZ.
Can 6066 be formed, bent or molded?
Extrudes and forges well at 400–480 °C but cold formability in T6 is poor — bend and cold-form in O or T4 and age afterwards.
What surface finishes work on 6066?
Takes hard sulfuric and chromic anodize well and paints/powder-coats readily; Cu makes clear/bright decorative anodize gray and blotchy, so specify architectural finish on 6061/6063 instead.
6066 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 | 0.9 – 1.8 | 1.4 |
| Fe | ≤ 0.5 | — |
| Cu | 0.7 – 1.2 | 0.95 |
| Mn | 0.6 – 1.1 | 0.8 |
| Mg | 0.8 – 1.4 | 1.1 |
| Cr | ≤ 0.4 | — |
| Zn | ≤ 0.25 | — |
| Ti | ≤ 0.2 | — |
| Others (each)each | ≤ 0.05 | — |
| Others (total)total | ≤ 0.15 | — |
| Al | balance | — |
6066-T451 — frequently asked
What is 6066-T451 used for?
6066-T451 is typically used for forged shafts, cycle rims, heavy extruded structural sections, high-strength machined brackets, forged suspension and linkage parts and hydraulic and pneumatic bodies. In short: high-strength forging alloy.
What is the yield strength of 6066-T451?
6066-T451 has a typical yield strength of 205 MPa (29.7 ksi) and a tensile strength of 360 MPa (52.2 ksi) — stronger than 54% of aluminum grades. Strength varies by condition: see the 11 listed tempers.
Is 6066-T451 easy to machine?
Reasonably — machinability is rated good (62/100, better than 55% of aluminum grades). One of the better-machining 6000-series alloys thanks to Cu and Mn — sharp polished-flute carbide tools, high speed, chip-clearing coolant; T6/T651 gives cleaner chips than T4.
Can 6066-T451 be welded?
With care — weldability is rated fair (40/100). Arc welding is discouraged (Cu-bearing, hot-crack and IGC prone); if required use 4043/4145 filler, low heat input and re-heat-treat plus age, expecting a weak HAZ.
What surface finishes work on 6066-T451?
Takes hard sulfuric and chromic anodize well and paints/powder-coats readily; Cu makes clear/bright decorative anodize gray and blotchy, so specify architectural finish on 6061/6063 instead.
Can 6066-T451 be formed, bent or molded?
Extrudes and forges well at 400–480 °C but cold formability in T6 is poor — bend and cold-form in O or T4 and age afterwards.
What is the maximum service temperature of 6066-T451?
6066-T451 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.
Can FabDigit make parts in 6066-T451?
Yes — 6066-T451 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- Aluminum Association International Alloy Designations and Chemical Composition Limits (Teal Sheets) — The Aluminum Association (2018)
- ASTM B221 — Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles and Tubes — ASTM International (2021)
- EN 573-3 / EN 755-2 — Wrought aluminium alloys, composition and extruded product properties — CEN (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Aluminum Standards and Data (typical mechanical & physical property tables) — 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.