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316 threading lube

shou shu

Plastic
Joined
Feb 7, 2006
Location
california
Anyone have any suggestions or recomendations on what they use? Im single pointing a 1 1/2 inch 6 tpi and am getting alot of tearing and insert breakdown. Am using Kennemetal inserts and trying to use as much surface speed as possible (thrreading away from the chuck) Thanks for the feedback.
 
I would not go overboard on the surface speed in threading 316. Maybe try 500 - 600 rpm on that diameter. 316 is a poor conductor and the chips get plenty hot, and tend to weld into a glob with little provocation. This pile-up then ruins the insert tip. Using cutting oil on stainless will raise one helluva smoke, because it is very hot in the cut zone.

Being a coarse thread, if I had plenty to do, I'd consider roughing it with a cheap TNMG 332 or 432 insert positioned just like a thread tool. The toolholder would have to have neutral side rake, negative front rake, but most of this style would be built that way. It might be necessary to drop the toolholder a little bit below center to gain some side clearance for it.

Try to finish thread cutting with your top notch taking cuts on alternate flanks of the thread. If possible, tune your program so that there are no spring passes, as this is when tool rubbing will scuff the work and damage the insert. Make the last cut .003" or so.
 
Ahhh stainless gotta love it.... i would go with advice already given, i've used the cheap TNMG route often to rough out and then finish with a laydown insert and it works very well and is a whole lot less stressfull than dulling or chipping nice expensive threading inserts, as for lubricant well as said it gets mighty hot in the cut zone with stainless and there will be alot of smoke but i use ambersil tufcut and it does a damn good job on stainless but is very very smokey.
 








 
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