Aluminum 6061
The default prototype alloy — easy to machine, stable, and the only one most prototype drawings should start from.
Cuts fast and holds tolerance. The one thing to watch is a long thin wall: it can chatter, and chatter is a finish problem before it is a dimension problem.
Quote a Aluminum 6061 partWhat we hold and what we can hold
Figures below are what our shops achieve on prototype quantities. A production order may justify tighter — or looser — tolerances, and that is a conversation, not a default.
| Property | Value |
|---|---|
| Typical use | Enclosures, heat sinks, fixtures, brackets, housings |
| Machinability | Excellent |
| Achievable tolerance | ±0.05 mm on critical features, ±0.10 mm typical |
| Typical lead time | 3–7 working days |
| Common grades | 6061-T6 · 6061-T651 · ADC12 (die-cast alternative) |
| Recommended finishes | Clear anodising · Black anodising · Bead blasting · Powder coating |
| Suitable processes | 3-axis milling · 5-axis milling · CNC turning · Vacuum casting |
What engineers ask about Aluminum 6061
These are the questions that come up on almost every Aluminum 6061 drawing. If your question is not here, send it with the drawing and we will answer it in the quote.
Is 6061 the right choice for a structural part?
For prototypes, yes — it is the reference point every other alloy is compared against. If the part will carry load in a final assembly and 7075 is available, we will tell you what the strength difference buys and what it costs in machinability and corrosion resistance.
Why did my anodised part come out a different shade than the sample?
Anodising is a chemical layer, so it takes colour from the alloy, the electrolyte and the bath condition. On a cosmetic part we run a three-piece trial and match against an approved sample before releasing the batch.
Can 6061 be used outdoors?
Bare 6061 will develop an oxide layer, which is usually acceptable. For a salt or marine environment we would either specify a different alloy or a sealing pass after anodising.
Where this material fits
Surface finishes for Aluminum 6061
When not to use Aluminum 6061
We would rather tell you on day one than ship you a part that was never the right answer. If one of these applies to your project, say so in the enquiry.
- Continuous chloride or marine exposure without a sealing pass after anodising
- Load-bearing parts where 7075 strength is the deciding factor
- Transparent or optical parts