How well do these work?

[DAB_Design]

Ebay item 3874805860

I've never used a boring bar like this. One thing I already don't like about them, is that they don't have indexable inserts. Do they even make them? I can't seem to find any.

[mc_n_g]

http://www.use-enco.com/CGI/INSRIT?P...&PARTPG=INLMK3

http://www.use-enco.com/CGI/INSRIT?P...&PARTPG=INLMK3

Are you talking about boring bars or boring heads??. Boring heads are normally, but not limited to, mills. Boring bars can be used in boring heads or normally on a lathe.

mc_n_g

[DAB_Design]

I guess I'm talking about boring heads and bars. To be used in a mill.

I've always used adjustable boring bars, so boring head is a term I'm not familiar with.

To be able to adjust the size, you either need an adjustable boring bar, or a solid boring bar in an adjustable boring head?

[Swede]

The ebay item you linked is a must-have item for a vertical mill. I cannot envision how or why one would be needed in a lathe.

The end of the head has a series of holes, often 0.50", to accept the cutter shank. The body is then offset from center with a hex wrench so the cutter describes an arc of basically any radius within the head's envelope. The offset portion rides in some very heavy dovetails. A few minutes of inspection will reveal its function right away; it's an easy tool to use and extremely effective.

The cutters are cheap and you don't need indexible tooling, they are easy to sharpen or you can simply trash them if they chip, they are that cheap.

[ViperTX]

Boring heads are used on lathes...they are mounted in the tailstock. You can also just use boring bars mounted to your toolpost. I suspect that's more of a preference. If you're boring something greater then 1 inch in diameter, I like indexable boring bars, you can get them with 0,-5 and +5 degree offsets, you don't have to worry about grinding you just replace the insert or index it. ENCO has these available, I suspect TRAVERS does also.