Drilling with an upcut end mill

deOs,

Endmills are not designed for drilling, but it might work if you use enough stepd to peck and get a good chip waste clearance.
Another way is to use a 3mm endmill and create a "pocket" hole. This also needs a good chip clearing but will certain work.
And last is to buy a proper drill bit, rember that you have to drill deeper due to the drill angle, so the bottom is not flat.

good luck

Hello Andrei.

Based on my experience, I would not use any end mill for drilling in any material. I have done this with very slow Z plunge rates (30 mm/min) with retracts after every 5 mm depth and still had problems with vibration, compacting of the spoil in the hole. I eventually bought a solid carbide conical nose jobber drill which works well. I still use very conservative Z plunge rates with retracts after every 5 mm though.

As CNCMiller says, end mills are not designed for drilling. The flute design will not clear chips and the centre of the bit will effectively be at zero velocity. End mills must be translated in the XY plane to work effectively.

Doug