AL · aluminium
Aluminium 6061-T6
The alloy most of our cycle times are quoted against. Published index around 300% on the B1112 = 100% scale, which matches what we see: it breaks a chip, it takes a polish, and it does not fight the tool.
Quoting this material
- Typical lead time
- 5–10 working days
- Condition
- T6 - solution heat treated and artificially aged at the mill
- Achievable finish
- Ra 1.6 µm typical · Ra 0.4 µm best
Choosing between two grades? 6061-T6 vs 7075-T6 compared →
Machined in-house to your drawing: see the precision CNC machining service and the machine and inspection capability it runs on.
Machinability
Our own 1–10 shop ranking, not a published index: 10 is free-cutting brass C360, 1 is Inconel 718. It ranks how a material behaves on the floor - cycle time, chip control and tool life together. Where a published index exists it is quoted in the note.
The alloy most of our cycle times are quoted against. Published index around 300% on the B1112 = 100% scale, which matches what we see: it breaks a chip, it takes a polish, and it does not fight the tool.
Properties as supplied
| Parameter | Value | Unit |
|---|---|---|
| Tensile strength | 310 | MPa |
| Yield strength (0.2%) | 276 | MPa |
| Elongation | 12 | % |
| Hardness | 95 | HB |
| Thermal conductivity | 167 | W/m·K |
| Modulus of elasticity | 68.9 | GPa |
Hardness, tensile and thermal figures are typical published values for the condition stated. Actual mill certificates govern; send the specification with the drawing and we confirm against the certificate before the material is cut.
Condition
T6 - solution heat treated and artificially aged at the mill
Heat treatment
There is no heat treatment after machining. The mill supplies T6 and nothing you do on a machine will raise it; welding drops the heat-affected zone back to O condition and it cannot be recovered without a full re-solution and age, which distorts the part.
Achievable surface finish
Ra 1.6 µm
Ra 0.4 µm
Finishes cleanly off a sharp insert. Anodising adds 5–20 µm per surface depending on the process, so a hard-anodised bore has to be allowed for.
Tooling and cutting parameters
Cutting speed
- 500–900 m/min (carbide)
Feed
- 0.15–0.40 mm/rev turning · 0.10–0.25 mm/tooth milling
Tooling
- Uncoated or ZrN carbide, high positive rake, polished flutes
Coolant
- Flood for deep pockets and tapping; air blast or MQL is enough for open milling
Starting points for carbide on a rigid setup, not a guarantee. The right numbers depend on the machine, the toolholder and the fixturing - ask and we will say what we would actually run.
Typical applications
- Aerospace brackets and fittings
- Semiconductor and vacuum-chamber components
- EV battery and inverter housings
- Instrument and optical mounts
- Industrial automation plates
DFM notes for this grade
- Thin walls below 1.5 mm will bow when the part is released from the plate - specify stress-relieved T6511 stock if the pocket is deep
- Anodising is not a masking process: a tight bore grows, and a thread grows with it, so allowed-for threads have to be called out on the drawing
- Sharp internal corners in a deep pocket need the smallest cutter on the shop floor, which throttles the feed rate - a 3 mm corner radius instead of 1 mm cuts cycle time visibly
Questions buyers ask
- Is 6082 a drop-in replacement for 6061?
- Close enough for most housings and brackets, and it is the more common grade in Europe. It is slightly stronger and slightly better in corrosion, but the tempering practices differ between mills, so if the part is flight-critical we machine what the drawing specifies rather than what we have on the rack.
- What tolerance can you hold on 6061?
- ±0.005 mm on a ground or fine-bored feature, ±0.025 mm on milled features as a working default. Below that the aluminium moves more with temperature than the machine does, so a 0.005 mm callout is really a callout about the temperature the part is measured at.