Hi, I am running an interrupted threading cycle. I have a 3/4 bar of 303 SS that is offset in our CNC lathe. It threads half way around then we flip the part and do it on the other side. I am have issues with chipping the tip off the insert. Sometimes I’ll get a tip to run 50 parts other times it breaks on the first part. Was wondering if anyone knows of a solution or maybe a higher grade insert for interrupted cutting?
Hello!
I was wondering if you could try a negative rake tool? Also you might try a full gometry insert. It may have a larger tip radios making it stronger. If you have a tool brand you like, give them a call they have great advice.
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going to sound crazy …start by trying 100 rpm with 0.002" DOC, Avoid spring passes. Use a cutting oil not coolant. Slowly increase rpm until tool life is unacceptable, then back off. If you cannot find a sweet-spot with carbide insert, try the same 100 rpm starting point & parameters with a HSS threading insert.
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Lathe inserts are not generally made for interrupted cuts. Find an insert with similar geometery for a milling operation like face milling. Most all milling inserts are formulated for interrupted cuts.
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