Small precision boring head

[arnoldb]

Very nice indeed Simon 

Peter: It's a very good idea to use the M6x0.5 thread.  First make and tap the nut.  Screw cutting the M6x0.5 feedscrew is not difficult; just hone up your toolbit nice and sharp on a fine oilstone.  I'd recommend HSS for this job - not carbide or inserts, as it's difficult to get the really sharp tip you need for the finer thread on those.  Clean the lathe's leadscrew very thoroughly and proceed with multiple small in-feed cuts with plenty of cutting fluid, and a spring-pass at the same setting every other pass; that makes for very nice and smooth finish.  Just test it with the nut for fit; it must screw on smoothly but without play.  The die nut will most likely give a slightly sloppy fit, unless it's of the split type - those you can open slightly for a better fit.

Kind regards, Arnold

[PeterE]

Thanks sco and Arnold! Your info is invaluable to me. It turned out that I have an HSS threading toolbit in one of my sets so that will be the one to use.

As you point out and as I guess, the die nut most probably will give a sloppy or loose fit and it is not a split die unfortunately (none of the two variants were).

BR

/Peter