- Joined
- Dec 7, 2015
- Messages
- 519
I bought some ALTiN coated carbide end mills for my mill the other day and am just now looking up formulas for how fast to spin them. I'm starting to think that maybe I made a mistake with:
The manufacturer recommends a 40% increase in SFM when the ALTiN coating is applied. 40% increase on 150 gives us a SFM of 210, and an RPM of = (3.82 * 210) / .5 = 1604rpm. Ok, yes, I can still deal with this.
However, when I start looking at smaller end mills like the 1/8" one in the set, being coated- I'd have to spin it at: (3.82 * 210) / .125 = 6417rpm!! This is far outside of the top speed of my mill. Had I bought standard HSS end mills, uncoated, then that 1/8" end mill would spin at: (3.82 * 100) / .125 = 3056rpm which is just a little higher than the max speed of my mill.
So what's the story here? I thought I was buying super awesome, high quality end mills- but maybe I bought a tool that is simply far outside of the capacity for my machine? Are coated carbide end mills better suited for CNC mills that can spin extremely fast?
- Going with carbide
- Going with coated carbide
The manufacturer recommends a 40% increase in SFM when the ALTiN coating is applied. 40% increase on 150 gives us a SFM of 210, and an RPM of = (3.82 * 210) / .5 = 1604rpm. Ok, yes, I can still deal with this.
However, when I start looking at smaller end mills like the 1/8" one in the set, being coated- I'd have to spin it at: (3.82 * 210) / .125 = 6417rpm!! This is far outside of the top speed of my mill. Had I bought standard HSS end mills, uncoated, then that 1/8" end mill would spin at: (3.82 * 100) / .125 = 3056rpm which is just a little higher than the max speed of my mill.
So what's the story here? I thought I was buying super awesome, high quality end mills- but maybe I bought a tool that is simply far outside of the capacity for my machine? Are coated carbide end mills better suited for CNC mills that can spin extremely fast?