If you want to work in inches then its Fz= feed in/min / rpm / N N=no of teeth so a 0.1mm Fz = 0.004in so an example 40in/min/12000/2= 0.0017" so this is too thin a chip... If the chip is too thin then you are trying to push the tool thru the material vs cutting it. This increases the tool load and increases the wear rate. Peter