spiral FLUTE taps was Re: General Tool Life Question

Hi,

We use 'em in 304SS, and they're wonderful. 6-32, 10-24, 10-32, 1/4-
20,5/16-18 in Procunier tapping heads. Mill and/or drillpress.
Westlube.

For blind holes, they really do spit the chips backatcha, and life
seems comparable to other types. I've not tried them manually (and
won't) as they have no pilot to speak of...

I have really tried to get away from cutting taps wherever possible.
The TRF (Thread Roll Forming) types are strong and work well, with no
chips to clean up after. Only broke one, and that was because the tap
drill size was incorrect (someone used a CUT style tapdrill size,
which is smaller than the TRF tapdrill size).

Do a lot of hand tapping with HSS 2 flute spiral point "gun" taps.
For through holes...

Hope this helps.

Ballendo

BTW, mostly 6061 alum, some 1018 and 12L14, 304 and 316SS, some
yellow brass and silicon bronze.

--- In CAD_CAM_EDM_DRO@y..., Hugh Currin <currinh@O...> wrote:
> Jon & all:
>
> I was told recently that these spiral flute taps work better than
straight
> taps for both hand and machine tapping. Does your, or anyone's,
experience
> back this up? What are the advantages of these sprial flute taps?
>
> Thanks.
>
> On Wednesday 16 January 2002 10:44 am, you wrote:
> > For blind holes, which I need to tap a lot, I use
> > spiral flute taps, which often list for $11 - $18, but I can
usually get
> > them for $4 - $7 when they are on sale.
> --
> Hugh Currin, PE
> Mechanical Engineering Technology
> Oregon Institute of Technology