Bright finish or coated Cobalt end mill?

[Birdpath]

Hi folks:

Thinking about buying some cobalt end mills from Suncoast tools (e.g. part 76422), rougher, five flute for general use in steel. Home hobby shop, not in a hurry, 2J Bridgeport mill. Should I get bright finish or pay more for coated mills (e.g. TiCN)? Can I get coated mills sharpened? Are coatings more important in mills running at higher speeds? Thanks for any input. Still pretty new at this deal. Best, Daniel

 

[MrWhoopee]

Get the bright finish. Coatings are for specific applications, which you don't have. Coated endmills can be sharpened, but the coating is removed from the cutting edge in the process. Coated endmills become important when trying to maximize metal removal and/or cutter life in production/CNC situations.

 

[Buffalo21]

the last batch of cobalt end mill I bought, I thought it was strange, the AlTin coated end mills were $1 - $2 cheaper than the uncoated ones of the same size. I bought 5 of the 1/4” 4 fl, center cutting and 5 of the 3/8”, all with 3/8” shanks.

 

[pontiac428]

They're all bright on the inside. Coatings really do extend life of the tool, and reduce friction at the cutting edge. Coatings that contain the metal that you want to use them for can cause fouling, like TiAlN is bad on aluminum, they say. I prefer to buy bright because I plan to gradually sharpen new end mills down to a little nub.