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.