Thought those fancy tool coatings were a gimmick until I tried a TiAlN endmill on some stainless

I used to just run whatever HSS or uncoated carbide was cheapest from Enco because I figured coatings were just marketing fluff for guys who wanted to impress each other. Then I got a job milling 304 stainless for a medical parts order about 6 months ago and burned through 4 endmills in one shift. My buddy who runs a job shop loaned me one of his TiAlN coated carbide mills and told me to just try it. That single tool ran the whole job and still looked decent at the end. The cost difference was like $8 more per tool, but it basically paid for itself in saved setup time and not having to swap inserts every 20 minutes. Has anyone else had a similar experience with a coating they thought was overhyped or am I just late to the party?

3 comments

3 Comments

avery2191mo ago

Man, I get what you're saying. A buddy of mine had the exact same thing happen with a TiAlN coated drill bit on some 316 stainless. He was drilling 3/8 holes for some brackets and snapped three HSS bits in about an hour. He was about to toss the whole job in the trash. Then his old foreman handed him one coated bit and it ate through the rest of the batch without even getting hot. He said the only reason he tried it was because the old guy was so sure about it, but he never went back to uncoated after that.

angela5871mo ago

My buddy in the same boat swore coating was a hoax until a TiN coated drill outlasted three HSS ones on 316.

williams.sage1mo ago

Nah, TiN is solid but on 316 you're better off with TiAlN or AlTiN. The aluminum in the coating handles the heat way better because 316 work hardens fast and generates a ton of friction. Your buddy got lucky with that TiN but it's mostly a general purpose coating. I had a job drilling through 1/2 plate and the TiAlN bit was still sharp after fifty holes while a regular TiN was done after twenty. The difference is noticeable once you push the feed rate up.