Boring bar shank oversized

[T. J.]

I recently bought a NOS Morse cobalt boring bar with a 3/4" shank on eBay. When I tried to install it in my Criterion DBL-203 boring head, it wouldn't fit. Its shank measures 0.749", while my other bars measure 0.747 - 0.748".

Is this a fluke, or do different manufacturers have different tolerances (i.e. do I need to stay away from Morse brand boring bars for this boring head)?

 

[mmcmdl]

Check for a burr on the end of the bar . Most heads have a +.0005 tolerance from nominal . Most bars have a -.0005 -..001 from nominal .

 

[mikey]

Morse is a well respected source of cutting tools and I have never seen a problem with them, although anything can happen with mass produced stuff. I would measure the hole in your boring head and measure the shank of your new boring bar and see if there is a mismatch. I agree that debris or a burr on either one may be the problem. If the shank is too big, I'm sure Morse will make it right.