Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

In article ,
says...
Strength of 3/4" iron pipe threads.

Thanks,

I think this was posted recently a few times, if you check google it
should turn up the answer for you.

--
Duncan Munro
http://metal.duncanamps.com

Yeah it was Stu himself a week ago. Maybe time for you to get a book, eh
Stu?

Todd L

"Duncan Munro" wrote in message
.. .
In article ,
says...
Strength of 3/4" iron pipe threads.

Thanks,

I think this was posted recently a few times, if you check google it
should turn up the answer for you.

--
Duncan Munro
http://metal.duncanamps.com

"Stu" wrote in message
om...
Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

Here ya' go, Stu:

3/4" iron pipe threads produce 32,450 ksi inverted shear strength. That is,
assuming you've torqued the joint to a value between 86.5 and 86.6 ft-lb,
backed off a half-turn, and re-tightened by 11/16 of a turn.

Enjoy!

Ed Huntress

In article , Ed Huntress
says...

3/4" iron pipe threads produce 32,450 ksi inverted shear strength.

Hmm. That sounds like a lot. Is this for the
special 'nobendium' alloy?

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

"jim rozen" wrote in message
...
In article , Ed Huntress
says...

3/4" iron pipe threads produce 32,450 ksi inverted shear strength.

Hmm. That sounds like a lot. Is this for the
special 'nobendium' alloy?

Yes, except that nobendium loses strength when you bend it.

Ed Huntress

In article , Ed Huntress
says...

Yes, except that nobendium loses strength when you bend it.

Oh, well. That's no problem.

I'm not strong enought to do *that*.

:^)

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Ed Huntress wrote: 3/4" iron pipe threads produce 32,450 ksi inverted shear
strength. That is, assuming you've torqued the joint to a value between 86.5
and 86.6 ft-lb, backed off a half-turn, and re-tightened by 11/16 of a turn.
^^^^^^^^^^^^^^^
Ed, I looked in the index of Machinery's Handbook, and couldn't find this.
So I turned all the pages, and STILL couldn't find it. I KNOW this will
come up again, so I'd love to know to look for it. Please hurry. I'm
holding my breath.

"Leo Lichtman" wrote in message
...

Ed Huntress wrote: 3/4" iron pipe threads produce 32,450 ksi inverted
shear
strength. That is, assuming you've torqued the joint to a value between
86.5
and 86.6 ft-lb, backed off a half-turn, and re-tightened by 11/16 of a
turn.
^^^^^^^^^^^^^^^
Ed, I looked in the index of Machinery's Handbook, and couldn't find this.
So I turned all the pages, and STILL couldn't find it. I KNOW this will
come up again, so I'd love to know to look for it. Please hurry. I'm
holding my breath.

It's written in secret code, right after the index.

Ed Huntress

Ed Huntress wrote:

It's written in secret code, right after the index.


In my 12th edition, it's written on the edge of the page, in green ink,
where it can only read by those having a high moral tone and heroic
studliness.

Kevin Gallimore




-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----

In article , axolotl says...

In my 12th edition, it's written on the edge of the page, in green ink,
where it can only read by those having a high moral tone and heroic
studliness.

Hmm. Could I see it, if the studliness were
'amazingly excessive,' and not merely heroic?

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Ed Huntress wrote:

"Stu" wrote in message
om...
Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

Here ya' go, Stu:

3/4" iron pipe threads produce 32,450 ksi inverted shear strength. That is,
assuming you've torqued the joint to a value between 86.5 and 86.6 ft-lb,
backed off a half-turn, and re-tightened by 11/16 of a turn.

Enjoy!

Ed Huntress

You can get at least 23.76% more than that if you use unobtanium pipe.

Jeff
--

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can smile when things are going wrong, you've thought of someone to
blame it on."

Jeff Wisnia wrote:

Ed Huntress wrote:


"Stu" wrote in message
.com...

Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

Here ya' go, Stu:

3/4" iron pipe threads produce 32,450 ksi inverted shear strength. That is,
assuming you've torqued the joint to a value between 86.5 and 86.6 ft-lb,
backed off a half-turn, and re-tightened by 11/16 of a turn.

Enjoy!

Ed Huntress


You can get at least 23.76% more than that if you use unobtanium pipe.

Jeff



Even Better than that, if you fill the pipe with heavy water, its extra
gravitational attraction will lessen the "pull" of the earths gravity by
about .000258758 g/M/L. Note that if you put a resivoir above it, the
larger you make it, the more you can hang from the pipe. To acheive
the ultimate suspensive force, you must couple your resivoir to an
ocean,... or at least one of the great salty lakes. You must use PVC
pipe for this coupling though, or else the free gravitrons will adhere
to a metal coupling pipe and you wont get anywhere.

mark

Group,

First let me apologize for posting my question more than one time.
The problem was the Google was 'hiding' my posts and I repeated them
because I believed that they were not posted. I asked Google to
'splain.

Why did I ask this questiion?

See my homebuilt elevator that 'hangs' on the threads of a single 3/4"
black iron pipe.


http://www.imagestation.com/album/?id=4288894713 Homebuilt Elevator

Thanks again,

BoyntonStu


Jeff Wisnia wrote in message ...
Ed Huntress wrote:

"Stu" wrote in message
om...
Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

Here ya' go, Stu:

3/4" iron pipe threads produce 32,450 ksi inverted shear strength. That is,
assuming you've torqued the joint to a value between 86.5 and 86.6 ft-lb,
backed off a half-turn, and re-tightened by 11/16 of a turn.

Enjoy!

Ed Huntress

You can get at least 23.76% more than that if you use unobtanium pipe.

Jeff

In article , Stu says...

Group,

First let me apologize for posting my question more than one time.
The problem was the Google was 'hiding' my posts and I repeated them
because I believed that they were not posted. I asked Google to
'splain.

They do that, down in the fine print they often say
that 'some similar search results were omitted, click
here if you want to see them' or something like that.

BTW if the machine is already built and works fine,
why investigate the tensile strength issue now?

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

See my homebuilt elevator that 'hangs' on the threads of a single 3/4"
black iron pipe.


http://www.imagestation.com/album/?id=4288894713 Homebuilt Elevator


It looks very nice, Stu. About the strength issue: Pipe threads are made to
seal against fluid leaks, and are nowhere near as strong as a straight
thread, because first one wall (say, the pipe) and then the other wall (the
fitting) tapers to a thin section. So you only have real thread strength
over a short section near the middle of the thread.

Secondly, black iron pipe isn't spec'd for tensile or compression strength.
It's spec'd on wall thickness, and, if you want to get fussy about it, it's
the hoop strength (the strength against expansion of fluids inside) that's
implicit in its specification. That, and allowance for corrosion, uneven
construction, and ham-fisted plumbers.

Thirdly, even a straight thread on a hollow tube is a complicated strength
issue. Thread strengths and standards are based on threading solid bar or
rod. When you thread a tube, the standard strength calculations go out the
window. Your minor diameter now is based on effective wall thickness as well
as the depth of thread. There also is an issue concerning the tendency of
the inner threaded piece to collapse from the angular forces imposed on it
by the 60-degree thread angles. That's not an issue with bar or rod.

If you have to deal with calculated strengths, the first thing you want to
do is to go to a mechanical tubing, rather than plumbing pipe. Then you'll
have to consult someone who knows his stuff on the thread-strength issue for
tubing. Either that, or use another method of assembly. You may actually
have plenty of strength for the application with pipe-threaded plumbing
pipe. But you won't be able to prove it, and, if liability is an issue,
you'd be dead meat.

Good luck.

Ed Huntress

In article , Ed Huntress
says...

It looks very nice, Stu. About the strength issue: Pipe threads are made to
seal against fluid leaks, and are nowhere near as strong as a straight
thread, because first one wall (say, the pipe) and then the other wall (the
fitting) tapers to a thin section. So you only have real thread strength
over a short section near the middle of the thread.

NPT threads are pretty much always sharp V form threads at
the root of the male threads. This, along with the generally
rough surface finish in black iron pipe, will cause failures
to occur at the distinct stress concentration at the root
of the threads.

I would suggest that the joints in question be static
tested for, say, five or so times the static load they
are expected to bear in use, to account for any dynamic
loading they might see.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

In article x_0ib.78702$Ri4.27008470
@news4.srv.hcvlny.cv.net, says...

Secondly, black iron pipe isn't spec'd for tensile or compression strength.
It's spec'd on wall thickness, and, if you want to get fussy about it, it's
the hoop strength (the strength against expansion of fluids inside) that's
implicit in its specification. That, and allowance for corrosion, uneven
construction, and ham-fisted plumbers.

ASTM A53 (plain old black pipe) does specify yield and
tensile strength. The AISC allows its use, the most common
use is naturally as columns. According to my 1973 Steel
Construction Manual Fy = 36ksi, the same as A36 structural
steel.


Thirdly, even a straight thread on a hollow tube is a complicated strength
issue. Thread strengths and standards are based on threading solid bar or
rod. When you thread a tube, the standard strength calculations go out the
window. Your minor diameter now is based on effective wall thickness as well
as the depth of thread.

Yup, this was my response to one of Stu's earlier posts,

"Assuming a stout flange, my SWAG is that failure would
occur at the root of the threads near the fitting, where
the wall of the pipe is thin due to the threads."

Ned Simmons

In article ,
Stu wrote:
Group,

First let me apologize for posting my question more than one time.
The problem was the Google was 'hiding' my posts and I repeated them
because I believed that they were not posted. I asked Google to
'splain.

Google is not the best way to post to usenet newsgroups. I do
know that it can be very slow to go from the posting to showing up in
the database. There are many other ways to post which don't involve
requiring a web browser to do it. It's strength is that it is a path to
access things posted to usenet a long time ago, long after normal
news servers have expired it.

Why did I ask this questiion?

See my homebuilt elevator that 'hangs' on the threads of a single 3/4"
black iron pipe.

Does this mean that you also haven't seen the various responses
to your (several) postings? In short, the answer seems to be that steel
pipe is not rated for structural use, and as a result, you won't find
the information in any handbook. Steel pipe is too variable in multiple
ways -- and the flanges into which you want to screw it are probably the
weakest link of the entire setup.


http://www.imagestation.com/album/?id=4288894713 Homebuilt Elevator

Hmm ... I encounter the following message:

"Before you view images from Homebuilt One Person Elevator,
you'll need to sign-in. If you're not already a member, now's
the time to join. Why join? Because ImageStation is all about
sharing. It's where you can store, edit, and share digital
images, and it's all FREE."

Well ... I don't believe in giving some random imaging service
my e-mail account (and perhaps other information), so they can spam me,
so all I will see is the first image.

However -- I don't think that *I* would want to trust that
assembly, from what I see of it in the one photo. Perhaps with machined
threaded pieces from a known steel in place of the cast or forged floor
flanges, and a thicker-walled pipe -- perhaps with straight threads,
instead of the usual tapered pipe threads, it *might* be a bit safer.

If it is only you who is going to ride it, you know how it is
made, and you can't sue yourself it if fails. If someone else is on it
when it fails, you really have no protection from a lawsuit, without an
engineering assessment of it from licensed professional structural
engineers.

Good Luck,
DoN.
--
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 ---

OK Stu , my profound apologies for being one of the reprobates ragging you about multiple posts.
Your project looks like a very creative job.

My curious mind forces me ask:

A: I don't recall seeing you mention why you built this rig Stu. Is there a handicapped person
living there who can't do stairs?

B: What are the alternate means for this person (if they are disabled) to safely get down and out if
there's a fire and the electric power is lost?

C: The offset position of that lifting pipe on the lift platform makes for quite a lot of bending
load on the joint in question. And maybe a bit of "bounce" when it stops at the top or when someone
steps on at that location. How is that pipe flange under the platform fastened to it so that it
won't tear loose.

D: I didn't "get" the safety brake concept from the photo, but it sounds interesting. Does it work
something like the jam washer on a screen door closer? Can you amplify the description for me? I
realize there's very little chance of it ever being needed, but did you actually test its
performance with a dummy load by snipping a temporary link in the winch cable while the elevator was
in motion?

Finally, I myself wouldn't trust the 3/4" black iron pipe threads for this job; not with a person's
safety depending on them. Assuming you can accomode assembling things in place with the platform
fastened to the pipe, I'd go with something better than hardware store pipe there and spend the
bucks to have it welded into a 1/4" thick steel plate (about one half the area of your platform) by
a certified welder, with a collar or sleeve welded to it and the plate as well.

Just my .02.

Jeff

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place the blame on."




Stu wrote:

Group,

First let me apologize for posting my question more than one time.
The problem was the Google was 'hiding' my posts and I repeated them
because I believed that they were not posted. I asked Google to
'splain.

Why did I ask this questiion?

See my homebuilt elevator that 'hangs' on the threads of a single 3/4"
black iron pipe.

http://www.imagestation.com/album/?id=4288894713 Homebuilt Elevator

Thanks again,

BoyntonStu

Jeff Wisnia wrote in message ...
Ed Huntress wrote:

"Stu" wrote in message
om...
Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

Here ya' go, Stu:

3/4" iron pipe threads produce 32,450 ksi inverted shear strength. That is,
assuming you've torqued the joint to a value between 86.5 and 86.6 ft-lb,
backed off a half-turn, and re-tightened by 11/16 of a turn.

Enjoy!

Ed Huntress

You can get at least 23.76% more than that if you use unobtanium pipe.

Jeff




--

Stu wrote:

Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

You just don't give up, do you Stu?

Jeff

--

Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can smile when things are going wrong, you've thought of someone
to blame it on."

And he wants us to register so we can watch 15 minutes of his dirty
movies. I don't want any spam so I'm not gonna register.

Nor am I gonna register my gun


On Sat, 11 Oct 2003 04:24:33 GMT, Jeff Wisnia
wrote:



Stu wrote:

Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

You just don't give up, do you Stu?

Jeff

What are you talking about?

Stu

FuhhKyu wrote in message . ..
And he wants us to register so we can watch 15 minutes of his dirty
movies. I don't want any spam so I'm not gonna register.

Nor am I gonna register my gun


On Sat, 11 Oct 2003 04:24:33 GMT, Jeff Wisnia
wrote:



Stu wrote:

Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

You just don't give up, do you Stu?

Jeff

Stu wrote:

Strength of 3/4" iron pipe threads.


Why not just make the same setup with a short piece of pipe and test in in a
press to see what it will break at?

Stu wrote:

What are you talking about?

Stu


I think he tried to copy a post response to you and got a message back from your "Automatic e-mail
verifier" Stu, the one for "Stu or Jan". It looks a somewhat like it might be of e-mail harvesting
scam. This is what it just sent to me:

************************************************** **********************************

Subject:
Please verify your Email address for us this one time. (Free) - 564018913810
Date:
Tue, 14 Oct 2003 12:49:02 -0400
From:
Automatic Email Verifyer (Stu or Jan)
To:
"Jeff Wisnia"

This is an automatic message from Stu or Jan.

In order to avoid SPAM Emails, We require that
every person do a one time verification of
their Email address. This step should only take
a few seconds. Loading the page will tell you
that your Email address has been verified.
To save time, you do NOT have to load the entire page.

Simply click on the hyperlink below to deliver the Email
that you sent to me with subject :

Machinest Handbook lookup request (Pleeeeze)


Once verified, all future Email will immediately be delivered.

Thanks,

The Email Verification Autoresponder


http://www.email-bouncer.com/verify.cfm?564018913810

This email is to verify :
Key : 564018913810

************************************************** *****************

Jeff

--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place the blame on."





FuhhKyu wrote in message . ..
And he wants us to register so we can watch 15 minutes of his dirty
movies. I don't want any spam so I'm not gonna register.

Nor am I gonna register my gun


On Sat, 11 Oct 2003 04:24:33 GMT, Jeff Wisnia
wrote:



Stu wrote:

Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

You just don't give up, do you Stu?

Jeff

Jeff Wisnia

I use Emailbouncer.com to avoid and eliminate all SPAM, Porn, and
Virus attacks.

The first time Emailer must verify the email address one time. Else,
a SPAMMer using any email address could get to my Inbox.

If you sent me a valid Email without Emailbouncer I would know your
email address.

BoyntonStu





wrote in message ...
Stu wrote:

What are you talking about?

Stu


I think he tried to copy a post response to you and got a message back from your "Automatic e-mail
verifier" Stu, the one for "Stu or Jan". It looks a somewhat like it might be of e-mail harvesting
scam. This is what it just sent to me:

************************************************** **********************************

Subject:
Please verify your Email address for us this one time. (Free) - 564018913810
Date:
Tue, 14 Oct 2003 12:49:02 -0400
From:
Automatic Email Verifyer (Stu or Jan)
To:
"Jeff Wisnia"

This is an automatic message from Stu or Jan.

In order to avoid SPAM Emails, We require that
every person do a one time verification of
their Email address. This step should only take
a few seconds. Loading the page will tell you
that your Email address has been verified.
To save time, you do NOT have to load the entire page.

Simply click on the hyperlink below to deliver the Email
that you sent to me with subject :

Machinest Handbook lookup request (Pleeeeze)


Once verified, all future Email will immediately be delivered.

Thanks,

The Email Verification Autoresponder


http://www.email-bouncer.com/verify.cfm?564018913810

This email is to verify :
Key : 564018913810

************************************************** *****************

Jeff

--
Jeff Wisnia (W1BSV + Brass Rat '57 EE)

"If you can keep smiling when things go wrong, you've thought of someone to place the blame on."





FuhhKyu wrote in message . ..
And he wants us to register so we can watch 15 minutes of his dirty
movies. I don't want any spam so I'm not gonna register.

Nor am I gonna register my gun


On Sat, 11 Oct 2003 04:24:33 GMT, Jeff Wisnia
wrote:



Stu wrote:

Strength of 3/4" iron pipe threads.

Thanks,

Boyntonstu

You just don't give up, do you Stu?

Jeff