My preference has been to generally use a 4flute coated carbide endmill for almost all my machining and only use a 2flute slot drill when slotting or if shavings could be a problem. I never really used a 3flute slot drill.
In my new company, they only really have 3flute slot drills and use 4flutes only for finishing aluminium jobs. I think the idea is to reduce tool inventory, as they can use the 3flute slot drill for all types of operations.
Can anyone give me their opinions and preferences.
Thanks.