Have Citizen M32 thread rolling 24UNC with several dia sizes of thread in stainless steel 303 using a Fette rolling head (Japan turn Key at Factory)
We used to get 2000 parts per set of rollers now it is less than 1000 parts per set of rollers.
There are signs of chipping at the front of the rollers where the crest of the thread form is broken away.
We use a Fuchs oil as the coolant and I believe after some use of the same oil for 12 Months its lubricant properties have broken down or the coolant has so much fine particals of metal mixed in the oil it is causing the rollers to fail or we need to change the grade of coolant oil
Your thoughts on this matter will be most apreciated