Hi Alan

In my experience, I have worked on projects that involve using cutters as small as 0.4mm ball noses, for production runs of 2,400-off components.

Aluminium is very forgiving. Running on a machine with a 10,000 or 12,000 rpm spindle... a 0.5mm ball nose at 10,000 amp & ~120mm/min, cut depth 0.2mm will run no issues.