Aluminum–magnesium–silicon · 6xxx series
6061 Aluminum Alloy
6061 is a magnesium-silicon alloy that responds to heat treatment. In T6 it reaches about 310 MPa tensile and 270 MPa yield, machines cleanly and welds reasonably, which is why it is the most widely specified structural aluminum alloy in general engineering.
Quote within 24 working hours · Certificate type stated on the quote
6xxx series · 6 tempers quoted · 2.700 g/cm³
At a glance
6061 Aluminum — The Short Version
| Alloy family | Aluminum–magnesium–silicon (6xxx) |
|---|---|
| Density | 2.700 g/cm³ |
| Tempers quoted | O · T4 · T451 · T6 · T651 · T6511 |
| Heat treatable | Yes — strength comes from solution treatment and ageing |
| Standards | ASTM B209 · ASTM B221 · EN 485 · EN 755 · GB/T 3880 |
| Forms supplied | Aluminum Sheet & Plate · Aluminum Bar & Rod · Aluminum Tube & Pipe · Aluminum Extrusion Profile · Aluminum Forged Ring |
Chemistry
6061 Chemical Composition Limits
Percent by weight. These are the registered limits, not a typical analysis — a heat that sits anywhere inside them is still 6061.
| Element | Limit (% wt) | Element | Limit (% wt) |
|---|---|---|---|
| Si | 0.40 – 0.80 | Fe | 0.70 max |
| Cu | 0.15 – 0.40 | Mn | 0.15 max |
| Mg | 0.80 – 1.20 | Cr | 0.04 – 0.35 |
| Zn | 0.25 max | Ti | 0.15 max |
| Other, each | 0.05 max | Other, total | 0.15 max |
| Al | Remainder |
Composition limits are the Aluminum Association registered ranges, which is what ASTM B209 and EN 573-3 both refer back to. Mechanical values are typical for the temper shown, not acceptance minima — the minima are set by the product standard, and the mill certificate reports the measured values for your heat.
Mechanicals
Typical Mechanical Properties by Temper
Room temperature, longitudinal direction. Use these to compare grades and tempers — the acceptance figures for your order come from the product standard and are reported on the mill certificate for the actual heat.
| Temper | Tensile (MPa) | Yield (MPa) | Elongation (%) | Thermal conductivity (W/m·K) |
|---|---|---|---|---|
| T6 | 310 | 270 | 10 | 170 |
Other tempers in the 6061 range — O · T4 · T451 · T6 · T651 · T6511 — are available to order. Values for those are quoted with the offer rather than assumed from this table.
Forms
6061 in the Forms We Supply
The same alloy behaves differently as coil, plate and extrusion because the rolling or extrusion route sets the temper and the surface. Pick the form first, then the temper.
Aluminum Sheet & Plate
Rolled flat product from 0.2 mm foil stock to 200 mm plate.
0.2 – 200 mm · 600 – 2,200 mm
Aluminum Bar & Rod
Round, square, hexagonal and flat bar; rolled or extruded.
— · Ø 5 – 400 mm
Aluminum Tube & Pipe
Seamless extruded, cold-drawn, and welded tube.
Wall 0.5 – 20 mm · OD 6 – 400 mm
Aluminum Extrusion Profile
Custom die extrusions — the section is drawn, not bought.
Wall 0.8 – 20 mm · Circumscribed Ø up to 400 mm
Aluminum Forged Ring
Seamless rolled ring for pressure boundary and rotating parts.
Wall 20 – 300 mm · Ø 200 – 4,000 mm
Where it is used
Typical End Uses for 6061
Industrial & Machining
Machining stock. Grain direction, residual stress relief (T651) and dimensional stability decide whether the part moves after it is cut.
Transport & Automotive
Weight reduction per body panel is the entire business case. Formability and weldability decide the grade.
Electronics & Heat Management
Heat sinks are an extrusion geometry problem: fin height, fin pitch and flatness tolerance. 6063-T5 holds fine fins that 6061 cannot.
Marine & Shipbuilding
Mg-alloyed plate resists seawater and welds without losing strength. This is the series classification societies expect to see on hull plate.
Selection
Choose 6061 When — and When Not To
Choose 6061 when
Machined parts, jigs and fixtures, structural brackets, truck and rail components, and anything that needs strength plus a decent anodized finish. T651 for thick plate that will be machined.
Think again if
Heavy weldments that must hold full strength — the heat-affected zone drops to roughly T4 and does not recover without re-heat-treatment. For welded marine structure use 5083 instead.
Before you ask
6061 — Questions Buyers Ask
6061-T6 or T651 for machined plate?
T651 whenever you are removing a lot of material from thick plate. T651 is stretched after quenching to relieve residual stress; without that, a machined pocket can distort after the part leaves the machine.
Is 6061 weldable?
Yes, with 4043 or 5356 filler, but joint strength drops sharply. The heat-affected zone loses the T6 condition, so a welded 6061 assembly typically designs to T4-level properties. Re-heat-treatment after welding is rarely practical.
How does 6061 anodize?
Well — it is the standard decorative and protective anodizing grade for structural parts. Type II films run 10–25 µm; hard anodizing (Type III) is available where wear resistance matters.
What is the difference between 6061 and 6082?
6082 has more silicon and manganese and is about 5–10% stronger; 6061 has better extrudability and is more available in North America. In Europe 6082 is the structural default; in North America it is 6061.
Does 6061 corrode in seawater?
It resists atmospheric and fresh-water corrosion well but is not a marine alloy. Salt immersion causes pitting, and 6061 is more susceptible than 5052 or 5083. Use it for marine deck fittings only with anodizing or a coating system.
Also compare
Other Grades in 6xxx
- 6082 AluminumAluminum–magnesium–silicon · O · T4 · T6
- All seven series →The full alloy map, from 1xxx to 8xxx
Often specified instead
- 6082 AluminumAluminum–magnesium–silicon · Crane and lifting structures, truck frames, machine frames, bridge and rail components — anywhere a European drawing calls up 6082 and the strength budget is tight..
- 7075 AluminumAluminum–zinc · Aerospace fittings and jigs, high-stress tooling, moulds and any part where strength per kilo decides the design.
Quote on 6061 Aluminum
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