MetalsWhat is 6061 aluminum and what is it used for? The most versatile structural aluminum
6061 aluminum (6061-T651) is the most versatile structural aluminum. In this guide we explain what 6061 aluminum is, its composition, its properties, what it is used for and the sizes we stock.
What is 6061 aluminum?
6061-T651 aluminum is a magnesium-silicon alloy with medium-to-high strength, low weight and good corrosion resistance. Its balance of strength, machinability and weldability makes it ideal for structural applications and precision machined parts.
Chemical composition of 6061 aluminum
This is the typical composition of 6061 aluminum (Commercial 6061-T651 / ASTM B209 and B211 / UNS A96061 / EN AW-6061 / DIN 3.3211 standard):
| Element | Contents | What for? |
|---|---|---|
| Silicon (Si) | 0.40 – 0.80 % | With magnesium it forms Mg2Si |
| Iron (Fe) | 0.70 % max. | Controlled impurity |
| Copper (Cu) | 0.15 – 0.40 % | Adds strength |
| Manganese (Mn) | 0.15 % max. | Alloying element |
| Magnesium (Mg) | 0.80 – 1.20 % | With silicon it forms Mg2Si: provides strength when heat treated |
| Chromium (Cr) | 0.04 – 0.35 % | Improves toughness and corrosion resistance |
| Zinc (Zn) | 0.25 % max. | Residual element |
| Titanium (Ti) | 0.15 % max. | Refines the grain |
| Others (each) | 0.05 % max. | Other elements, kept limited |
| Others (total) | 0.15 % max. | Sum of others, limited |
| Aluminum (Al) | Balance | Base metal |
6061 properties and temper
6061 is the most widely used structural aluminum because of its balance. In T651 temper it offers a tensile strength on the order of 310 MPa and a hardness close to 95 HB, with very good machinability, weldability and corrosion resistance. It is heat treatable (6000 series, magnesium-silicon); the T651 temper indicates solution heat treated, stress relieved by stretching and artificially aged, which gives it dimensional stability, ideal for precision machined parts. It also anodizes very well.
What is it for? Applications of 6061
6061 aluminum is mainly used in:
- Machinery bases and plates
- Fixtures and tooling
- Structures and structural shapes
- Automotive and transportation components
- Precision machined parts (CNC)
- Molds and mold bases
- Welded structures and assemblies
- Marine and boating hardware
- Decorative and protective anodized parts
Forms and sizes we carry
At NAT MAC we stock 6061 aluminum in these forms and sizes:
| Package size | Sizes |
|---|---|
| Plates | 1/8" – 6" (3.18 – 152.4 mm) |
| Round bars | 1/4" – 12" (6.35 – 304.8 mm) |
| Flat bars | 1/4" – 1-1/2" (6.35 – 38.1 mm) |
If you need a particular size, tell us which one and we will gladly source it for you.
6061 equivalents and standards
6061 aluminum is also identified by these standards: Commercial 6061-T651 / ASTM B209 and B211 / UNS A96061 / EN AW-6061 / DIN 3.3211. You can see how to read them in our article on metal standards.
In summary
- 6061-T651 is a magnesium-silicon aluminum, the most versatile structural grade
- Heat treatable; ~310 MPa and ~95 HB, with good weldability and corrosion resistance
- Excellent for precision machining, anodizing and structures
- Ideal for bases, fixtures, structures, CNC parts and molds
- We carry it in plates, round bars, flat bars, cut to size
Why buy your 6061 aluminum at NAT MAC?
We have more than 54 years of experience as an industrial supplier and ISO 9001 certified quality. We carry quality aluminum and help you choose the right alloy for your project.
- Quality 6061 Aluminum, backed and traceable
- Material cut to the size you need
- Advice on choosing between 3003, 6061 and 7075 for your part
- Plate, round bar, flat bar and sheet depending on the alloy
- On-time deliveries and competitive prices
Tell us what you are going to make and in what dimensions, and we will recommend the right alloy and form. Request your free quote.
Sources: data sheet from our NAT MAC catalog (composition, sizes and applications) and public references from the aluminum industry. Values are for reference and may vary by standard, temper and heat.
