boring bar inserts

[dallen]

(07-27-2013, 08:19 AM)PixMan Wrote: That's a common boring bar, but I still don't understand the design. It appears that as you tighten the screw it would naturally push the insert out of the pocket. Unless of course it's a left hand threaded screw.

I have two solid carbide boring bars that take TPG/TPU 22x size inserts. They are old Valenite VNCD 7462 and VNCD 7463. The bars use a clamp that fastens via a screw coming up from the bottom of the bar, to reduce chances of chips wrapping around the fasteners.



I'm usually well versed in carbide insert tooling, but your photo of your boring bar has me confused. Your photo shows an insert clamped with no shim/chipbreaker on top. There does appear to be something strange under the insert though, and the insert seems a bit small on the I.C. size for that pocket. What am I getting wrong here?

Pixman sorry I just saw this post. will send a PM

yes the bar has a screw with a head that has hash marks around it, and is lefthand threaded.

Rick the piece that you see under the insert in the photo is something that I found that would fit under the insert to raise it high enough that the screw would clamp down on the insert. I really like the bar it cuts well and is a decent size for most of what I do for large diameter short bores.

Think I gave 19 dollars for it off of evil bay back before everyone wanted new prices for stuff that was damaged.