On Thu, 22 Jul 2010 15:32:39 -0700, Garlicdude
wrote:

DoN. Nichols wrote:
On 2010-07-22, Garlicdude wrote:
Existential Angst wrote:
Awl --

Sorta like a round coupling nut, tapped 1 3/4" through, axially.
Will be drilled, rigid tapped on a fadal.

Had cut tapped these before, just wondering if form tapping would be better,
what others would do.
I know form tapping will require more clamping power, which is a minor
minus. Coolant will be a MW-150 soluble oil. About 800 pcs.

If it's not broke, don't fix it. I'd stay with the cut tap as you've already
had success with that method.

The major question is how often it will be removed and replaced
in service. The form tapping will work-harden the 12L14 and orient the
grain so it will be stronger and more wear resistant.

If there is no requirement to increase the strength (and if you
are using 12L14, I would suspect that strength is not a primary concern)
then keep using the cut tap.

Enjoy,
DoN.



I hear this "formed threads are stronger" argument a lot. My thinking is if
your design is such that the small difference between a cut and a formed thread
makes a difference between success and failure maybe you should rethink your
materials or design.

In 12L14 I think it's a mute point.

Best,
Steve

Granted, considering the use of 12L14, the strength issue is not quite
all there is....

.....That said, the difference is pullout strength in even low carbon
steel between cut thread and formed is actually quite high...

.....I have a part that I make for a "local Department of Defense" near
you....that's the US Navy, thru contractors...that used to be made
with a 7/16-14 thread that we used a cut tap on...we played around
with a form tap and the pullout force went from almost 1200 pounds of
direct pull to fali to nearly 2600 pounds....

.....base material was 1018 cold rolled....1" diameter....2"
long....drilled thru and tapped halfway from each side...pull test was
with eye bolts threaded 5/16" deep.

Your results may vary....but forming DOES make for a much stronger
thread, I believe.

Mike

wrote in message
...
On Thu, 22 Jul 2010 15:32:39 -0700, Garlicdude
wrote:

DoN. Nichols wrote:
On 2010-07-22, Garlicdude wrote:
Existential Angst wrote:
Awl --

Sorta like a round coupling nut, tapped 1 3/4" through, axially.
Will be drilled, rigid tapped on a fadal.

Had cut tapped these before, just wondering if form tapping would be
better,
what others would do.
I know form tapping will require more clamping power, which is a minor
minus. Coolant will be a MW-150 soluble oil. About 800 pcs.

If it's not broke, don't fix it. I'd stay with the cut tap as you've
already
had success with that method.

The major question is how often it will be removed and replaced
in service. The form tapping will work-harden the 12L14 and orient the
grain so it will be stronger and more wear resistant.

If there is no requirement to increase the strength (and if you
are using 12L14, I would suspect that strength is not a primary concern)
then keep using the cut tap.

Enjoy,
DoN.



I hear this "formed threads are stronger" argument a lot. My thinking is
if
your design is such that the small difference between a cut and a formed
thread
makes a difference between success and failure maybe you should rethink
your
materials or design.

In 12L14 I think it's a mute point.

Best,
Steve

Granted, considering the use of 12L14, the strength issue is not quite
all there is....

....That said, the difference is pullout strength in even low carbon
steel between cut thread and formed is actually quite high...

....I have a part that I make for a "local Department of Defense" near
you....that's the US Navy, thru contractors...that used to be made
with a 7/16-14 thread that we used a cut tap on...we played around
with a form tap and the pullout force went from almost 1200 pounds of
direct pull to fali to nearly 2600 pounds....

....base material was 1018 cold rolled....1" diameter....2"
long....drilled thru and tapped halfway from each side...pull test was
with eye bolts threaded 5/16" deep.

Curiosity -- how do you tap from each side and have the threads meet?

--
Ed Huntress




Your results may vary....but forming DOES make for a much stronger
thread, I believe.

Mike

wrote in message
...
On Thu, 22 Jul 2010 15:32:39 -0700, Garlicdude
wrote:

DoN. Nichols wrote:
On 2010-07-22, Garlicdude wrote:
Existential Angst wrote:
Awl --

Sorta like a round coupling nut, tapped 1 3/4" through, axially.
Will be drilled, rigid tapped on a fadal.

Had cut tapped these before, just wondering if form tapping would be
better,
what others would do.
I know form tapping will require more clamping power, which is a minor
minus. Coolant will be a MW-150 soluble oil. About 800 pcs.

If it's not broke, don't fix it. I'd stay with the cut tap as you've
already
had success with that method.

The major question is how often it will be removed and replaced
in service. The form tapping will work-harden the 12L14 and orient the
grain so it will be stronger and more wear resistant.

If there is no requirement to increase the strength (and if you
are using 12L14, I would suspect that strength is not a primary concern)
then keep using the cut tap.

Enjoy,
DoN.



I hear this "formed threads are stronger" argument a lot. My thinking is
if
your design is such that the small difference between a cut and a formed
thread
makes a difference between success and failure maybe you should rethink
your
materials or design.

In 12L14 I think it's a mute point.

Best,
Steve

Granted, considering the use of 12L14, the strength issue is not quite
all there is....

....That said, the difference is pullout strength in even low carbon
steel between cut thread and formed is actually quite high...

....I have a part that I make for a "local Department of Defense" near
you....that's the US Navy, thru contractors...that used to be made
with a 7/16-14 thread that we used a cut tap on...we played around
with a form tap and the pullout force went from almost 1200 pounds of
direct pull to fali to nearly 2600 pounds....

....base material was 1018 cold rolled....1" diameter....2"
long....drilled thru and tapped halfway from each side...pull test was
with eye bolts threaded 5/16" deep.

Your results may vary....but forming DOES make for a much stronger
thread, I believe.

This is really inneresting!
I wonder if this "pullout difference" is proportionally greater in still
softer materials, like aluminum.
--
EA



Mike

On Thu, 22 Jul 2010 21:30:32 -0500, wrote:

On Thu, 22 Jul 2010 15:32:39 -0700, Garlicdude
wrote:

DoN. Nichols wrote:
On 2010-07-22, Garlicdude wrote:
Existential Angst wrote:
Awl --

Sorta like a round coupling nut, tapped 1 3/4" through, axially.
Will be drilled, rigid tapped on a fadal.

Had cut tapped these before, just wondering if form tapping would be better,
what others would do.
I know form tapping will require more clamping power, which is a minor
minus. Coolant will be a MW-150 soluble oil. About 800 pcs.

If it's not broke, don't fix it. I'd stay with the cut tap as you've already
had success with that method.

The major question is how often it will be removed and replaced
in service. The form tapping will work-harden the 12L14 and orient the
grain so it will be stronger and more wear resistant.

If there is no requirement to increase the strength (and if you
are using 12L14, I would suspect that strength is not a primary concern)
then keep using the cut tap.

Enjoy,
DoN.



I hear this "formed threads are stronger" argument a lot. My thinking is if
your design is such that the small difference between a cut and a formed thread
makes a difference between success and failure maybe you should rethink your
materials or design.

In 12L14 I think it's a mute point.

Best,
Steve

Granted, considering the use of 12L14, the strength issue is not quite
all there is....

....That said, the difference is pullout strength in even low carbon
steel between cut thread and formed is actually quite high...

....I have a part that I make for a "local Department of Defense" near
you....that's the US Navy, thru contractors...that used to be made
with a 7/16-14 thread that we used a cut tap on...we played around
with a form tap and the pullout force went from almost 1200 pounds of
direct pull to fali to nearly 2600 pounds....

....base material was 1018 cold rolled....1" diameter....2"
long....drilled thru and tapped halfway from each side...pull test was
with eye bolts threaded 5/16" deep.

Your results may vary....but forming DOES make for a much stronger
thread, I believe.

Mike

Indeed it does. Nearly all DOD high strength stuff requires formed
threads these days, rather than cut ones, based on conversations with
clients of mine such as Fasterner Tech....

http://www.ftc-usa.com/

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

On Thu, 22 Jul 2010 23:07:47 -0400, "Existential Angst"
wrote:

wrote in message
.. .
On Thu, 22 Jul 2010 15:32:39 -0700, Garlicdude
wrote:

DoN. Nichols wrote:
On 2010-07-22, Garlicdude wrote:
Existential Angst wrote:
Awl --

Sorta like a round coupling nut, tapped 1 3/4" through, axially.
Will be drilled, rigid tapped on a fadal.

Had cut tapped these before, just wondering if form tapping would be
better,
what others would do.
I know form tapping will require more clamping power, which is a minor
minus. Coolant will be a MW-150 soluble oil. About 800 pcs.

If it's not broke, don't fix it. I'd stay with the cut tap as you've
already
had success with that method.

The major question is how often it will be removed and replaced
in service. The form tapping will work-harden the 12L14 and orient the
grain so it will be stronger and more wear resistant.

If there is no requirement to increase the strength (and if you
are using 12L14, I would suspect that strength is not a primary concern)
then keep using the cut tap.

Enjoy,
DoN.



I hear this "formed threads are stronger" argument a lot. My thinking is
if
your design is such that the small difference between a cut and a formed
thread
makes a difference between success and failure maybe you should rethink
your
materials or design.

In 12L14 I think it's a mute point.

Best,
Steve

Granted, considering the use of 12L14, the strength issue is not quite
all there is....

....That said, the difference is pullout strength in even low carbon
steel between cut thread and formed is actually quite high...

....I have a part that I make for a "local Department of Defense" near
you....that's the US Navy, thru contractors...that used to be made
with a 7/16-14 thread that we used a cut tap on...we played around
with a form tap and the pullout force went from almost 1200 pounds of
direct pull to fali to nearly 2600 pounds....

....base material was 1018 cold rolled....1" diameter....2"
long....drilled thru and tapped halfway from each side...pull test was
with eye bolts threaded 5/16" deep.

Your results may vary....but forming DOES make for a much stronger
thread, I believe.

This is really inneresting!
I wonder if this "pullout difference" is proportionally greater in still
softer materials, like aluminum.

Yes..it is. Though not as great a difference.

Gunner

One could not be a successful Leftwinger without realizing that,
in contrast to the popular conception supported by newspapers
and mothers of Leftwingers, a goodly number of Leftwingers are
not only narrow-minded and dull, but also just stupid.
Gunner Asch

Existential Angst wrote:
Awl --

Sorta like a round coupling nut, tapped 1 3/4" through, axially.
Will be drilled, rigid tapped on a fadal.

Had cut tapped these before, just wondering if form tapping would be
better,
what others would do.
I know form tapping will require more clamping power, which is a
minor
minus. Coolant will be a MW-150 soluble oil. About 800 pcs.

If it's not broke, don't fix it. I'd stay with the cut tap as you've
already
had success with that method.

The major question is how often it will be removed and replaced
in service. The form tapping will work-harden the 12L14 and orient
the
grain so it will be stronger and more wear resistant.

If there is no requirement to increase the strength (and if you
are using 12L14, I would suspect that strength is not a primary
concern)
then keep using the cut tap.

Enjoy,
DoN.



I hear this "formed threads are stronger" argument a lot. My thinking
is if
your design is such that the small difference between a cut and a formed
thread
makes a difference between success and failure maybe you should rethink
your
materials or design.

In 12L14 I think it's a mute point.

Best,
Steve

Granted, considering the use of 12L14, the strength issue is not quite
all there is....

....That said, the difference is pullout strength in even low carbon
steel between cut thread and formed is actually quite high...

....I have a part that I make for a "local Department of Defense" near
you....that's the US Navy, thru contractors...that used to be made
with a 7/16-14 thread that we used a cut tap on...we played around
with a form tap and the pullout force went from almost 1200 pounds of
direct pull to fali to nearly 2600 pounds....

Mebbe someone used the wrong tap drill???

Apropos of Garlic et al comments, it would seem the diff is closer to
10%.

Another machinist I know did this same type of test, got a similar result
from his recollection, and provided two cites, which show a max of 10%.

http://www.ctemag.com/dynamic.articles.php?id=197

http://www.bhamfast.com/pdfs/bhamfast_rtct.pdf

--
EA

I don't know the specifics for individual materials. When I was a tooling
editor I was supplied with a variety of studies and test results, and they
did show wide variability with material types and states of initial
hardness.

One phone call to a major manufacturer of thread-forming taps is worth ten
days of guessing and speculation. The guys at Emuge were always especially
helpful to me.

I dunno.... somehow I think if that 1200 vs 2600 lb result were typical,
cut taps would be falling out of favor/use REAL fast....

That would be because I goofed....a little transpositional error....

.....SHOULD have read 2100 vs. 2600

opps....sorry about that

I'll go hit myself with a wet noodle now.

Mike

Existential Angst wrote:
Awl --

Sorta like a round coupling nut, tapped 1 3/4" through, axially.
Will be drilled, rigid tapped on a fadal.

Had cut tapped these before, just wondering if form tapping would be
better,
what others would do.
I know form tapping will require more clamping power, which is a minor
minus. Coolant will be a MW-150 soluble oil. About 800 pcs.

If it's not broke, don't fix it. I'd stay with the cut tap as you've
already
had success with that method.

The major question is how often it will be removed and replaced
in service. The form tapping will work-harden the 12L14 and orient the
grain so it will be stronger and more wear resistant.

If there is no requirement to increase the strength (and if you
are using 12L14, I would suspect that strength is not a primary concern)
then keep using the cut tap.

Enjoy,
DoN.



I hear this "formed threads are stronger" argument a lot. My thinking is
if
your design is such that the small difference between a cut and a formed
thread
makes a difference between success and failure maybe you should rethink
your
materials or design.

In 12L14 I think it's a mute point.

Best,
Steve

Granted, considering the use of 12L14, the strength issue is not quite
all there is....

....That said, the difference is pullout strength in even low carbon
steel between cut thread and formed is actually quite high...

....I have a part that I make for a "local Department of Defense" near
you....that's the US Navy, thru contractors...that used to be made
with a 7/16-14 thread that we used a cut tap on...we played around
with a form tap and the pullout force went from almost 1200 pounds of
direct pull to fali to nearly 2600 pounds....

....base material was 1018 cold rolled....1" diameter....2"
long....drilled thru and tapped halfway from each side...pull test was
with eye bolts threaded 5/16" deep.

Curiosity -- how do you tap from each side and have the threads meet?

There was no need for the threads to be matched up....there was some
crossover at the middle, but it didn't matter...the part only had to
have .875" of full form thread from each side...3/4" of the mating
stud is all that threaded into the part.

And as I mentioned in another post in this thread...I messed up....I
typed 1200 vs 2600....it should have read 2100 vs. 2600.

oops

Mike

wrote in message
...
Existential Angst wrote:
Awl --

Sorta like a round coupling nut, tapped 1 3/4" through, axially.
Will be drilled, rigid tapped on a fadal.

Had cut tapped these before, just wondering if form tapping would be
better,
what others would do.
I know form tapping will require more clamping power, which is a
minor
minus. Coolant will be a MW-150 soluble oil. About 800 pcs.

If it's not broke, don't fix it. I'd stay with the cut tap as you've
already
had success with that method.

The major question is how often it will be removed and replaced
in service. The form tapping will work-harden the 12L14 and orient
the
grain so it will be stronger and more wear resistant.

If there is no requirement to increase the strength (and if you
are using 12L14, I would suspect that strength is not a primary
concern)
then keep using the cut tap.

Enjoy,
DoN.



I hear this "formed threads are stronger" argument a lot. My thinking
is
if
your design is such that the small difference between a cut and a formed
thread
makes a difference between success and failure maybe you should rethink
your
materials or design.

In 12L14 I think it's a mute point.

Best,
Steve

Granted, considering the use of 12L14, the strength issue is not quite
all there is....

....That said, the difference is pullout strength in even low carbon
steel between cut thread and formed is actually quite high...

....I have a part that I make for a "local Department of Defense" near
you....that's the US Navy, thru contractors...that used to be made
with a 7/16-14 thread that we used a cut tap on...we played around
with a form tap and the pullout force went from almost 1200 pounds of
direct pull to fali to nearly 2600 pounds....

....base material was 1018 cold rolled....1" diameter....2"
long....drilled thru and tapped halfway from each side...pull test was
with eye bolts threaded 5/16" deep.

Curiosity -- how do you tap from each side and have the threads meet?

There was no need for the threads to be matched up....there was some
crossover at the middle, but it didn't matter...the part only had to
have .875" of full form thread from each side...3/4" of the mating
stud is all that threaded into the part.

Aha. Since the part was a cylinder, I thought that might be the case. But
you never know...


And as I mentioned in another post in this thread...I messed up....I
typed 1200 vs 2600....it should have read 2100 vs. 2600.


Yeah, I caught that. Transpositions can be interesting g

oops

Mike

--
Ed Huntress

wrote:

That would be because I goofed....a little transpositional error....

....SHOULD have read 2100 vs. 2600

opps....sorry about that

I'll go hit myself with a wet noodle now.

Mike

That is the b*tch of usenet, no way to edit now. In the civilized days we could fix our
mistakes. to some degree.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

On Fri, 23 Jul 2010 18:06:46 -0400, Wes
wrote the following:

wrote:

That would be because I goofed....a little transpositional error....

....SHOULD have read 2100 vs. 2600

opps....sorry about that

I'll go hit myself with a wet noodle now.

Mike

That is the b*tch of usenet, no way to edit now. In the civilized days we could fix our
mistakes. to some degree.

Civilized days, as in "300baud BBS" days, Wes?

--
Exercise ferments the humors, casts them into their proper channels,
throws off redundancies, and helps nature in those secret distributions,
without which the body cannot subsist in its vigor, nor the soul act
with cheerfulness. -- Joseph Addison, The Spectator, July 12, 1711

Larry Jaques wrote:

That is the b*tch of usenet, no way to edit now. In the civilized days we could fix our
mistakes. to some degree.

Civilized days, as in "300baud BBS" days, Wes?

Even 1200 baud.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller