ccfl wrote:Are there any brazed carbide boring bars out there that have the correct geometry?
Sure! Even imports. Here's an example:
http://www.ebay.com/itm/3-Pcs-Cabide-Br ... 1997462676
Maybe one of us missed something here. Is there something wrong with the Mesa Tool indexable bars (other than their being indexable and therefore have no place in the home shop/hobby environment so on and whatever)?
The point I tried to make is that buying a cheap bar isn't a good idea if it doesn't serve the intended purpose. I may have misunderstood your thoughts, though, as I now think the link you provided was for an inexpensive bar, one that uses inserts. I got the impression that the brazed bars were what you referenced. In that case, I apologize.
The bar in the link appears to be made properly, but it is also intended for use with a lathe. That doesn't mean you couldn't use it with a boring head, assuming the shank was the proper size. The one real negative is you have no choice in over-all length. Boring bars intended for use with boring heads generally permit installation in random orientation, so you can tailor the tool to the purpose, to say nothing of being able to choose various lengths, which limits spring and chatter. The other issue, which can be important, is that you can't introduce the bar to the bore with additional clearance, as you would using it with a lathe. Chips become troublesome when the shank is too close to the bore, as it would be with that specific bar.
I rarely encourage the home shop to pursue carbide, be it insert or brazed. Unless one has a machine that truly benefits from its use, HSS will generally yield superior results. The exceptions are when machining highly abrasive or hard materials. Otherwise, you can beat carbide's performance by properly grinding HSS. For boring, where tool pressure is always a concern, carbide simply is not a great choice.
Harold