Can plug tap sometimes mean second and sometimes bottoming?

Here is RS's plug taps selection, some of them look like they get close to the bottom, others less so.
https://uk.rs-online.com/web/c/hand-...ons=4294885797

The names seem to vary from website to website.

Is there a definitive answer?

ta

On 07/01/2021 13:22, misterroy wrote:
Can plug tap sometimes mean second and sometimes bottoming?

Here is RS's plug taps selection, some of them look like they get close to the bottom, others less so.
https://uk.rs-online.com/web/c/hand-...ons=4294885797

The names seem to vary from website to website.

Is there a definitive answer?

ta

when I was serving my engineering apprentceship many moons ago, I was
told that taps are named as First, Second, and Plug taps

A plug tap does not have any tapering of the threads, while the first
tap has quite a bit, and the 2nd tap has about half as much.

I hope that helps

On Thursday, 7 January 2021 at 14:28:02 UTC, RobH wrote:
On 07/01/2021 13:22, misterroy wrote:
Can plug tap sometimes mean second and sometimes bottoming?

Here is RS's plug taps selection, some of them look like they get close to the bottom, others less so.
https://uk.rs-online.com/web/c/hand-...ons=4294885797

The names seem to vary from website to website.

Is there a definitive answer?

ta

when I was serving my engineering apprentceship many moons ago, I was
told that taps are named as First, Second, and Plug taps

A plug tap does not have any tapering of the threads, while the first
tap has quite a bit, and the 2nd tap has about half as much.

I hope that helps
+1

On Thursday, January 7, 2021 at 2:28:02 PM UTC, RobH wrote:
On 07/01/2021 13:22, misterroy wrote:
Can plug tap sometimes mean second and sometimes bottoming?

Here is RS's plug taps selection, some of them look like they get close to the bottom, others less so.
https://uk.rs-online.com/web/c/hand-...ons=4294885797

The names seem to vary from website to website.

Is there a definitive answer?

ta

when I was serving my engineering apprentceship many moons ago, I was
told that taps are named as First, Second, and Plug taps

A plug tap does not have any tapering of the threads, while the first
tap has quite a bit, and the 2nd tap has about half as much.

I hope that helps
You live and learn. I never knew that. I recently bought one of those combined drill bit and taps and was surprised it worked quite well in 6mm aluminium amd some softwood.

In message ,
misterroy writes
Can plug tap sometimes mean second and sometimes bottoming?

Here is RS's plug taps selection, some of them look like they get close
to the bottom, others less so.
https://uk.rs-online.com/web/c/hand-...threading-taps
/?applied-dimensions=4294885797

The names seem to vary from website to website.

Is there a definitive answer?

I rather think things have moved on since my 6 weeks in the apprentice
school 1960 or so.

We were shown how to drill holes and tap threads. Electrical component
manufacturer so we learned a lot about BA threads:-)

Hand taps came in packs of 3 (first, second and plug). Looking back,
they were made of carbon steel and rather brittle. Half turn forward and
quarter back to break the swarf.

I think the idea of the taper was that the tap would follow the hole
rather than cut the thread at an angle. The second tap followed the
threads formed by the first cut. The plug tap was only used if the hole
had a bottom.

Modern stuff is much stronger with better control of hardness. I suppose
RS assume their market is manufacturing where machine tools will ensure
threads are cut parallel.

ta

--
Tim Lamb

On 07/01/2021 13:22, misterroy wrote:


Can plug tap sometimes mean second and sometimes bottoming?

Yup... a plug tap is the same as bottoming one - no taper at the end, so
needs a mostly already threaded hole to be able to carry on and do the
last bit in a blind hole.

Here is RS's plug taps selection, some of them look like they get close to the bottom, others less so.
https://uk.rs-online.com/web/c/hand-...ons=4294885797

The names seem to vary from website to website.

Not sure those pictures actually match the descriptions in many cases.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 07/01/2021 13:22, misterroy wrote:
Can plug tap sometimes mean second and sometimes bottoming?

Here is RS's plug taps selection, some of them look like they get close to the bottom, others less so.
https://uk.rs-online.com/web/c/hand-...ons=4294885797

The names seem to vary from website to website.

Is there a definitive answer?

ta


Yes use Tracy Tools who specialise in taps.

In article ,
Tim Lamb wrote:
I think the idea of the taper was that the tap would follow the hole
rather than cut the thread at an angle.

Sadly, you still need to keep it square to achieve this.

A tip that might help some. Put the tap in your pillar drill. Work square
in its vice. Turn the chuck by hand while applying downwards pressure via
the handle.

--
*IF ONE SYNCHRONIZED SWIMMER DROWNS, DO THE REST DROWN TOO?

Dave Plowman London SW
To e-mail, change noise into sound.

On 07/01/2021 16:48, John Rumm wrote:
On 07/01/2021 13:22, misterroy wrote:


Can plug tap sometimes mean second and sometimes bottoming?

Yup... a plug tap is the same as bottoming one - no taper at the end, so
needs a mostly already threaded hole to be able to carry on and do the
last bit in a blind hole.

Here is RS's plug taps selection, some of them look like they get
close to the bottom, others less so.
https://uk.rs-online.com/web/c/hand-...ons=4294885797


The names seem to vary from website to website.

Not sure those pictures actually match the descriptions in many cases.


This is a proper plug tap:
https://uk.rs-online.com/web/p/threading-taps/0152249/

"Dave Plowman (News)" writes:

A tip that might help some. Put the tap in your pillar drill. Work square
in its vice. Turn the chuck by hand while applying downwards pressure via
the handle.

Cutting compound is always helpful, too. At a previous place of work it
was Trefolex (green snot).

--
Alan J. Wylie https://www.wylie.me.uk/

Dance like no-one's watching. / Encrypt like everyone is.
Security is inversely proportional to convenience

In message , "Dave Plowman (News)"
writes
In article ,
Tim Lamb wrote:
I think the idea of the taper was that the tap would follow the hole
rather than cut the thread at an angle.

Sadly, you still need to keep it square to achieve this.

A tip that might help some. Put the tap in your pillar drill. Work square
in its vice. Turn the chuck by hand while applying downwards pressure via
the handle.

Yes. I also use the lathe for anything that can be clamped in the chuck.
Gripping HSS in the tailstock takes some doing.


--
Tim Lamb