I am using a Hertel HBBC-C250R5-4.0-285 boring bar. .25 shank with .285 min bore. With the first bar the end twisted off the carbide shank in just 8-9 parts. I am cuttin .01 deep @.004 with 400sfm. It has thru tool coolant so it should have been flushing the chips out. The material is 4140crs and was chipping not making stringers.
Is that too much for a brazed shank tool? The insert may have chipped a second or 2 before I got it stooped.
I jokingly took it to our welding shop and asked them to rebraze it!! He said the odds were that the braze job had a flaw in it for it to spin off.
I have used brazed tools many time and never had this problem. But this my first carbide shank boring bar so was it going too fast for that little bar?
Is that too much for a brazed shank tool? The insert may have chipped a second or 2 before I got it stooped.
I jokingly took it to our welding shop and asked them to rebraze it!! He said the odds were that the braze job had a flaw in it for it to spin off.
I have used brazed tools many time and never had this problem. But this my first carbide shank boring bar so was it going too fast for that little bar?