Three months fighting with surface finish on 316 stainless

Been running a job for a pump manufacturer here in Tulsa and could not get the surface finish below 125 RMS no matter what I tried. Swapped inserts, slowed down the spindle, even tried a different coolant mix. Finally an old timer from the shop next door told me to try a wiper insert with a 0.031 radius. First pass after that gave me a 63 RMS finish. Has anyone else had luck with wiper inserts for finishing tough stainless?

2 comments

2 Comments

angela_park20d ago

Are you running with a pretty light depth of cut on that finish pass? I've found wiper inserts are a game changer for stainless but you gotta dial in the feed rate just right or they chatter something awful. That .031 radius sounds about right though, too big and you'll get nasty vibration. Glad that old timer steered you in the right direction, sometimes the simple stuff is what gets missed.

eric_carr19d ago

Wait, wait wait. ARE YOU TELLING ME you actually TORCHED a $600 endmill on a test coupon? @angela_park, that's insane. I've smoked some pricey tools in my day but that's a whole different level of ouch. Makes my skin crawl just thinking about the sound it probably made right before it let go. That's the kind of mistake you only make ONCE, let me tell you.