Aluminium Alloys
Aluminium alloys are light (about one-third the weight of steel), corrosion resistant and very machinable, used for housings, brackets, fixtures, heat sinks and structural parts. Common grades include 6061/6082 (general), 7075 (high strength) and 5083 (marine plate).
What it is
Wrought alloys are grouped by series: 2xxx (copper, high strength, e.g. 2024), 5xxx (magnesium, marine, e.g. 5083), 6xxx (magnesium-silicon, general purpose, e.g. 6061, 6063, 6082) and 7xxx (zinc, highest strength, e.g. 7075). Temper codes like T6 describe heat treatment.
Aluminium machines fast with good finish and can be anodised, hard anodised or powder coated.
Typical applications
- Machined housings and brackets
- Jigs, fixtures and automation parts
- Heat sinks and electrical parts
- Aerospace and automotive parts
- Marine and structural components
Materials & grades
- 6061-T6 / 6082-T6
- 6063 (extrusions)
- 7075-T6 / T651
- 2024-T3/T351
- 5083 / 5052
Points to consider
- 7075 is strongest but less corrosion resistant and not weldable by fusion.
- 6061/6082 give the best all-round balance and anodise well.
- Use 5083 for marine and welded plate structures.
- Mind galvanic corrosion when in contact with steel or copper.
Frequently asked questions
Which aluminium alloy is best for machining?
6061-T6 and 6082-T6 are the most common all-round choices; 7075 where maximum strength is needed; 2011 for free machining.
What does T6 mean?
A temper: solution heat treated and artificially aged for high strength.
Is 7075 aluminium weldable?
Not by conventional fusion welding without losing strength and risking cracking; 6061 and 5083 weld much better.