1mm end mill depth of cut in aluminium.

[cropwell]

You do realize that OA is just bullshit for high helix. All cutters are open architecture.!! .

No I didn't realise it was bullshit. I thought it was a combination of a fishtail end and a more open helix. I have found end mills with a flat end are much more prone to clagging.

BTW Sorotec recommend a spindle speed of 50K 7mm/sec feed and 1 or 2mm/sec Z feed for up to 1.2mm cutters. With those parameters I would expect to melt through the metal unless you clear the debris. Chip size must be fine dust.

For 2 and 3mm cutters I use single flute with more success.