Re: Speed of Tapping Head? - tap styles

wow, you can't beat that link.

but I have been using the Enco catalogue as in the back with all
dimmentional data for taps and drills they also have pipe taps and
roll form tap and drill data.

Typically 75% is what is listed. and I usually go one smaller drill
to get a fractional instead of a number drill. I don't recommed it,
but I have not broken a 10-32 or 1/4-20 (yet)

and.... if you do break one, there is no chip clearance to allow you
to use Jon's EDM set-up to remove it super easy. you would have to
but away the whole body, not just the small web of a standard tap.

Dave

--- In CAD_CAM_EDM_DRO@y..., "jmkasunich" <jmkasunich@y...> wrote:
> --- In CAD_CAM_EDM_DRO@y..., "turbulatordude" <davemucha@j...>
wrote:
> > <snip>
> > Spiral flute are much weaker and are typicaly used
> > on softer materials like Aluminum. but for aluminum
> > I use self forming taps.
>
> > Makes a better hole, burnishes the inside so the threads
> > are not as soft, and does not leave any chips. And they
> > are available in bottom tap, so you can tap deeper on a
> > hole without pulling out to remove chips.
>
> I've been thinking about trying thread-forming taps.
> I read somewhere that you have to use larger tap drills
> with forming taps to make up for the fact that the tap
> doesn't remove any metal. How do I select the right tap
> drill size - info for thread-forming taps isn't in
> Machinery's Handbook or any of the other books I have.
>
> John Kasunich