Overheard a new guy say he never changes his end mills until they break

Was grabbing inserts at the supply counter and heard a trainee say that to his lead. Had a chat with him later about how I usually swap mine after 40 hours of cut time on aluminum, saved me from scrapping a $200 part twice this year. Anyone else got a hard rule for when they swap tools or do you just wing it?

2 comments

2 Comments

betty1441d ago

Buddy of mine runs a small job shop and swears by swapping his end mills every 10 hours on stainless, even if they still look good. He showed me this one time we were working on a batch of custom brackets, pulled a tool that had maybe 8 hours on it and it had a tiny chip you couldn't see without a loupe. Ran his finger along it and said that one would have snapped on the next pass for sure. I figure it's better to be safe than sorry, especially when the material costs are what they are these days.

blakem821d ago

Wait, so he's really timing it down to the hour like that? Makes me think of this one time I was helping a buddy swap out a wheel bearing on his old F-150, and he swore you had to torque the axle nut to exactly 220 foot-pounds or the whole hub would grenade on the highway. We eyeballed it with a breaker bar and a prayer, and sure enough, six months later that bearing was singing like a chorus of angry bees. Maybe I should start buying my end mills by the six-pack and swapping 'em out like I'm changing oil, 'cause I've definitely snapped a few on stainless and blamed the material instead of my own lazy tooling habits.