Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.

I saw something like that, on the base of a camera, back in the film days.
The threaded taper would atach the camera to a tripod. Other than that, I
havn't seen such.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"phaedrus" wrote in message
...
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.

On 7/29/2012 8:00 AM, phaedrus wrote:
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.


Pipe threads are tapered... It makes it more likely to seal when tight.

"phaedrus" wrote in message
...
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and
was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.

Please elaborate further. Pipe taps are tapered, and spring winding
mandrels could be mistaken for taps.

jsw

No, it's not a pipe thread; very much steeper taper than a pipe
thread...

One such as I refer to appears in South Bend's handbook, How to Run a
Lathe at p.82. Sorry I have no facilities to upload a scan of the
picture.

Jim Wilkins wrote:
"phaedrus" wrote in message
...
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and
was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.

Please elaborate further. Pipe taps are tapered, and spring winding
mandrels could be mistaken for taps.

jsw

BTW, is there a FAQ for this group?

On Sun, 29 Jul 2012 05:00:32 -0700 (PDT), phaedrus
wrote:

Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.

Pipe perhaps.

Oil drilling pipe tool joints are also taper threaded.
Cheers,
John B.

On Jul 29, 7:00*am, phaedrus wrote:
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.

http://www.moparmusclemagazine.com/t...air/index.html

"phaedrus" wrote in message
...
No, it's not a pipe thread; very much steeper taper than a pipe
thread...

One such as I refer to appears in South Bend's handbook, How to Run a
Lathe at p.82. Sorry I have no facilities to upload a scan of the
picture.


The picture in the SB book is just an illustration. Exaggerated to make the
setup clear.
If you need a to see something modern, threaded with that much taper look at
a tapered buffing spindle.

Paul K. Dickman

On Sun, 29 Jul 2012 07:25:23 -0700 (PDT), phaedrus
wrote:

No, it's not a pipe thread; very much steeper taper than a pipe
thread...

One such as I refer to appears in South Bend's handbook, How to Run a
Lathe at p.82. Sorry I have no facilities to upload a scan of the
picture.

http://wewilliams.net/SBLibrary.htm 44 page booklet.
P.82 does not compute. Was it another handbook?

(Unfortunately, I probably can't help you but I'm curious, just the
same.)

--
It takes as much energy to wish as to plan.
--Eleanor Roosevelt

On Sun, 29 Jul 2012 05:00:32 -0700, phaedrus wrote:

Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of the
threaded section is constantly varying, what can it possibly be screwed
into? I cannot imagine any nut or internal thread that would accommodate
such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

No one's mentioned wood screws yet, which are tapered along their length,
or sheet metal screws, which are tapered at the nose.

Aren't taps tapered?

Spring winding mandrels -- I never thought of that.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

On 7/29/2012 7:00 AM, phaedrus wrote:
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.

I once ran a job on a CNC turning center for a threaded taper to make
self tapping plugs for leaks in oil pipelines. The plugs were cut from
hex stock and then hardened.

The leak was drilled out to one of several standard sizes, the right
size plug twisted in, then welded in place.

These were much more tapered than standard pipe threads.

David

"phaedrus" wrote in message
...
No, it's not a pipe thread; very much steeper taper than a pipe
thread...

One such as I refer to appears in South Bend's handbook, How to Run
a
Lathe at p.82. Sorry I have no facilities to upload a scan of the
picture.

I suspect that drawing exaggerates the length to make the taper more
evident than it would be on a real pipe tap.

http://www.hycrack.co.uk/

jsw

On Sun, 29 Jul 2012 08:17:10 -0400, Stormin Mormon wrote:
"phaedrus" wrote ...
I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

I saw something like that, on the base of a camera, back in the film days.
The threaded taper would attach the camera to a tripod. Other than that, I
haven't seen such.

I haven't seen any threaded tapers for tripod-attaching, just 1/4-20
or 3/8-16 straight threads, but mechanical remote shutter releases
often have a tapered thread, as clearly seen in following photo.
http://en.wikipedia.org/wiki/File:OldCamera_CableRelease.jpg

--
jiw

On Sunday, July 29, 2012 8:53:54 AM UTC-7, Tim Wescott wrote:
On Sun, 29 Jul 2012 05:00:32 -0700, phaedrus wrote:

I've seen pictures of threaded tapers being machined on lathes and was

wondering what the hell use they are?

No one's mentioned wood screws yet, which are tapered along their length,

or sheet metal screws, which are tapered at the nose.

Aren't taps tapered?

Modern taps aren't really tapered, the threads are just on a tapered shaft
(the top of the crest is ground off of the leading teeth, so cutting is
progressive and not done all with the first tooth). But, old-timey taps
WERE tapered, so you could get any tightness of nut you wanted.

This was important when bolts were made with threading-plate type
dies (with poor diameter control) on forged rods (again, with poor
diameter control).

Another tapered-screw application is seen on the pilot of auger-type
wood boring bits. Yet another, is sometimes seen on citrus juicers.

On Sun, 29 Jul 2012 10:03:58 -0700, whit3rd wrote:

On Sunday, July 29, 2012 8:53:54 AM UTC-7, Tim Wescott wrote:
On Sun, 29 Jul 2012 05:00:32 -0700, phaedrus wrote:

I've seen pictures of threaded tapers being machined on lathes and
was

wondering what the hell use they are?

snip
Another tapered-screw application is seen on the pilot of auger-type
wood boring bits. Yet another, is sometimes seen on citrus juicers.

Which reminds me of the puree-ing attachment on our Kitchen-aid mixer,
which is a long tapered screw into a conical screen.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

"phaedrus" wrote in message
...
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.


From a mechanical standpoint, a steeply tapered thread is capable of
releasing upon a relatively few turns.

"Tim Wescott" wrote

Aren't taps tapered?
Tim Wescott

The threads aren't (except for pipe). The taper is a separate grind
that creates the cutting edges. Run a nut onto one and examine the
free play.

jsw

I'll start writing it.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"phaedrus" wrote in message
...
BTW, is there a FAQ for this group?

"PrecisionmachinisT" wrote in message
news:L6WdncYJR_178IjNnZ2dnUVZ_hadnZ2d@scnresearch. com...

"phaedrus" wrote in message
...
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.


From a mechanical standpoint, a steeply tapered thread is capable of
releasing upon a relatively few turns.


Yes, and still have the strength of something with many threads engaged.
This is why it is used on drill pipe and also cable releases for camera
shutters.

To answer the OP's second question, the female thread is also tapered.

"phaedrus" wrote in message
...
BTW, is there a FAQ for this group?

There is one.

Scott Logan used to post a link to it every month, but I think he got so
disgusted with the political bs that he gave up.

http://w3.uwyo.edu/~metal/faqa.html

Paul K. Dickman

On Sun, 29 Jul 2012 05:00:32 -0700 (PDT), phaedrus
wrote:

Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.
=================
API [American Petroleum Institute] drill stem, collar and
bit threads.

http://ballots.api.org/ecs/sc5/ballo.../5B_3064ag.pdf
http://www.practicalmachinist.com/vb...47/index2.html
http://www.kennametal.com/images/pdf...ngTechData.pdf





--
Unka' George

"Gold is the money of kings,
silver is the money of gentlemen,
barter is the money of peasants,
but debt is the money of slaves"

-Norm Franz, "Money and Wealth in the New Millenium"

On 2012-07-29, phaedrus wrote:
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Well ... pipe threads are commonly tapered. It provides greater
sealing force as you drive the male thread into the female one.

Other than that -- if you have a longer thread (e.g. a screw),
you can push it into the hole a ways before the threads engage -- acting
as a guide.

There are probably other reasons to have them, but these are the
two which come immediately to mind.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2012-07-29, phaedrus wrote:
No, it's not a pipe thread; very much steeper taper than a pipe
thread...

O.k. That reminds me of another use. The arbors on which
buffing wheels are mounted. You need a right-hand thread on one side
of the grinder used to drive it, and a left-hand one on the other side.
Just push the buffer on, then switch on and it self tightens.

One such as I refer to appears in South Bend's handbook, How to Run a
Lathe at p.82. Sorry I have no facilities to upload a scan of the
picture.

Probably a buffing wheel arbor. Or just a demonstration on how
to do it. O.K. Looking at the copy which I have here, it actually
states in the description "Tapered screw threads, such as pipe threads
.... " Obviously, the one being shown is not a pipe thread, but it could
be used as the arbor for a buffing wheel. Or just to train an
apprentice on how to do it.

This is in Volume 1 Edition 50 which happens to be within reach.

If I had a matching taper tap, I might use it for studs designed
to screw in and wedge really tight.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2012-07-29, phaedrus wrote:
BTW, is there a FAQ for this group?

Yes -- but at least a decade out of date. Whoever was
maintaining it (at a college) must have retired, and the files are just
still there (last I checked), along with archives of many years of
postings until that script was shut down. It was not a particularly
smart script, so if you are on a Windows system, be warned that it
archived a few copies of a virus current at the time. :-)

Here is the URL:

http://w3.uwyo.edu/~metal/

and it is still there.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 7/29/2012 08:00, phaedrus wrote:
Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.



Electric foundry furnace electrode threads.

--
Steve Walker
(remove brain when replying)

On Sun, 29 Jul 2012 05:00:32 -0700 (PDT), phaedrus
wrote:

Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.
Steeply threaded tapers are used sometimes to connect things like the
drill stem used for drilling oil wells. Once they have loosened just a
little bit they unscrew fast. So only a few turns will engage a long
length of thread. Look for API threads.
Eric

On Wed, 01 Aug 2012 08:47:32 -0700, wrote:

On Sun, 29 Jul 2012 05:00:32 -0700 (PDT), phaedrus
wrote:

Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.

Kindly disabuse me of my ignorance if you can, thanks.

P.
Steeply threaded tapers are used sometimes to connect things like the
drill stem used for drilling oil wells. Once they have loosened just a
little bit they unscrew fast. So only a few turns will engage a long
length of thread. Look for API threads.
Eric
Last time I lathe cut a tapered thread was to replace a lost drain
plug for a sail boat - I strongly suspect it was senior son who lost
it then asked me to make the replacement. Anyhow, it worked out OK.
---

Gerry :-)}
London,Canada

wrote:

Hi guys,

I've seen pictures of threaded tapers being machined on lathes and was
wondering what the hell use they are? I mean, since the diameter of
the threaded section is constantly varying, what can it possibly be
screwed into? I cannot imagine any nut or internal thread that would
accommodate such a piece of work.


When the taper is fairly small, the thread serves to "jam" in the female
part, expanding the female, and creating a better seal than would a
straight thread. Ordinary pipe threads are tapered for that reason.

LLoyd