Alloys / 6063-T5 / T6
6063-T5 / T6 Aluminum
The extrusion alloy, not the machine-from-solid alloy. Built to flow through a die, and it shows up on a CNC quote as end-machining on an already-extruded profile.
What it is
6000 series, aluminum-magnesium-silicon, lower alloy content than 6061. T5: cooled from the extrusion process and artificially aged, no separate solution treatment. T6 adds a full solution treatment for higher strength.
Machining
Machines acceptably but a shade softer and gummier than 6061, most noticeable on small drills and taps. Rarely bought as bar stock to machine a part from solid, it arrives as an extrusion or heat sink profile that only needs facing, drilling and tapping at the ends.
Finishing and joining
Anodizes clearer and more consistently than 6061 because it carries less iron and copper, which is why architectural and cosmetic extrusions are specified in 6063. Conducts heat somewhat better than 6061 too, the other common reason it appears on a heat sink drawing.
Where it turns up
- Heat sinks and cold plate extrusions
- Enclosure rails and frame extrusions
- Architectural and cosmetic anodized profiles
Read further
- Why an extrusion alloy shows up on a machining drawingRead the guide
- Type II vs Type III anodizeRead the guide
At a glance
| Yield strength | 214 MPa |
| Density | 2.7 g/cm³ |
| Weldability | 5 / 5 |
| Anodizing | 5 / 5 |
| Corrosion resistance | 4 / 5 |
| Strength for weight | 2 / 5 |
| Stays flat | 3 / 5 |
| Machinability | 4 / 5 |
Scores run 1 to 5, editorial judgements for comparison, not measured values. Yield is a typical published figure for this temper, not a guarantee for your lot.
Full property table for all alloys: alloy selector.
Questions
Is 6063-T5 / T6 weldable?
Yes, 6063-T5 / T6 welds without special difficulty. It is one of the more forgiving alloys on this list to join.
Does 6063-T5 / T6 anodize evenly?
Yes, it takes a Type II or Type III anodize evenly, in clear or colour, and is a safe choice for a visible cosmetic part.