Group Buy - End Mills?

[Tenson]

I haven't tried the single flute eBay ones yet, though I have ordered some. I have tried the 2 flute and 4 flute K2 and the 4 flute X5070. I found 4 flutes gives a better finish than 2 flutes and the shorter flutes of the X5070 give better finish than the longer K2.

[JAZZCNC]

I found 4 flutes gives a better finish than 2 flutes and the shorter flutes of the X5070 give better finish than the longer K2.

Single flute give better finish than 2, 3, 4 flute due to better chip clearence and not recutting chips which often happens with 4 flute if the feeds and spindle speeds are not spot on.
It's much more critical S&F are spot on giving correct chip load when using multi flute cutters.! If not they wear quickly due to heat and the finish gets rubbish fast.!!

Shorter cutters will always tend to give a better finish anyway due to less tool flex. I always do a full depth 0.1mm finish pass when machining Ali and wanting decent finish so even the cheap chinese cutters give a good finish.