Is your tool height correct? Normally wear on the bottom would mean the tool is way too high.
I've been making these custom bolts out of 5/8 heat treated hex, they switched up the material on me to 4140 heat treated, my roughing insert isn't lasting as long as it used to, using KYOCERA CNMG 432 PS CA5525. My machines RPM only goes to 2000, I've used a feed of .012 / .01 , with a wide variety of depths of cut, and the weird thing is, the insert is wearing on the bottom not the front.
Please help,
Whats happening
Thank you Bob.
Is your tool height correct? Normally wear on the bottom would mean the tool is way too high.
Jim Dawson
Sandy, Oregon, USA
Do you mean centered, Yes, when it faces there is no nipple.
The bottom of the insert should never see the material. I'm a bit confused here, are you saying that the the wear is on the bottom of the insert, the part next to the insert holder rather than the normal cutting tip? The only way I can figure out for that to occur is if the spindle was rotating backwards, or the tool holder rake angle is not correct such that the bottom of the insert is hitting the work before the tip.
Can you post a picture of the setup and a damaged insert.
Jim Dawson
Sandy, Oregon, USA
Yes I will, when I get home, The machine I'm talking about is in my garage not at work.
Another thought, above you said that there ''is no nipple'' when facing. If the tool bit was too high, there would not be a nipple, but the insert would wear on the bottom because the tip would be above the C/L.
Jim Dawson
Sandy, Oregon, USA