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1/8 IPS Thread ???

11B4VLA

Aluminum
Joined
Jan 9, 2008
Location
Wimberley, TX
I searched but couldn't find anything. This must have come up before so forgive me. Lamp fixtures apparently use a straight pipe thread. I have looked in some of my machinist books (I'm an amateur homeshop guy) and can't find much. I want to drill and tap a hole for a lamp fixture nipple. The nipple is about 0.386 inches in diameter measuring across the tops of the threads.

At my local Ace HW they show the designation for these nipples as 1/8 IPS. I believe the TPI is 27. Does the IPS stand for Iron Pipe Straight? I'm not familiar with pipe thread designations and can't figure out the 1/8 either. What on earth does this stand for?

Do I want to buy a 1/8 NPS tap to tap this guy and therefore a tap drill "S"?

Thanks in advance.
-Art
 
"I" = internal?

P = pipe - but you prolly already got there eh?

S = strait


I'm not familiar with pipe thread designations and can't figure out the 1/8 either. What on earth does this stand for?

Your serious? You never used pipe fittings before? Pipe sizes are sized for the internal bore of the pipe, although in many of the smaller cases (especially 1/8") the bore is off nominal by quite a margin.

W/O looking - yes - 1/8NPS is likely a letter S. (National Pipe Strait.)


Also - 1/8 pipe is 27 TPI.


While it is great that the local hdwr was able to help you out like this - you can save yourself many future haertaches (attacks?) by NOT buying hdwr quality cutting toys! And I kant stress this nearly enough when it comes to TAPS! They can be used succesfully in thread repair - but not for cutting new. (Your milage may vary.)


------------

Think Snow Eh!
Ox
 
Okay, but if 1/8 means 1/8" what does this refer to? Clearly the inside diameter of this is greater than 1/8". The S tap drill is 0.3480 inches, so I still don't understand the nomenclature of 1/8. Can you help or point me to an explanation?

Oh, are you saying that the internal diameter of the male nipple is 1/8"??? That must be it. Am I right?

Thanks,
-Art
 
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Okay, but if 1/8 means 1/8" what does this refer to? Clearly the inside diameter of this is greater than 1/8". The S tap drill is 0.3480 inches, so I still don't understand the nomenclature of 1/8. Can you help or point me to an explanation?

Thanks,
-Art

I can point you at Google. Maybe "pipe size" will get you there.

You already got the short, accurate explanation from Ox. If you want more, find it yourself. The Internet has all the answers if you will bother to search.

Larry
 
So Vance, why do you think google did not find IPS? Can you show me a query that will get that? A discussion on the Home Machinist board opined that it meant Iron Pipe Straight. Are your responses always so helpful or did you just pick me on a bad night?

If it is so straightforward why don't you post a link to the definition of IPS?

Thanks for very little other than entertainment.
-Art
 
Good Links, Thanks

Carl and Professor: Very interesting links. BTW, Professor, your link says that IPS is Iron Pipe Size not Iron Pipe Standard. So no wonder I couldn't measure anything that is 1/8" since the designation is historical and not current by measurement.

So I think that I would be correct in using a non-tapered NPS 1/8-27 tap and an "S" drill as the tap drill. According to
http://www.engineersedge.com/manufacturing/pipe-tap-drill-chart.htm

Okay, then, I think I get it.
Many Thanks,
-Art
 
11B4VLA,

You've got it right on your tap and drill size, you could also use a 11/32 drill bit if you currently have one without buying a S drill if don't have one of these.

I find google to less and less usable (for me), if you type in IPS, standard for IPS you get all kinds of crap before you find anything referring to Iron Pipe Size. After all there are a lot of acroymns that use IPS which none meaning Iron Pipe Size.

Pipe sizes and their designations along with the proper taps can get confusing, since many of us and others have probably been around since the original IPS (Iron Pipe Size) standards.:D A lot of times we create our own standard based upon the new and the old ie., IPS (Iron Pipe Straight) vs the newer NPS as defined below.

The problem with standards as once you get use to using it, then along comes some newer standard that tries to narrow the window by adding more standards.:crazy: Pipe sizes are roughly denoted based on the ID, however it's the OD that remains the constant. Example: Schedule 10, 40, 80, 120 all have the same OD, while their wall thickness varies due to the pressure they can handle. 1/8 inch pipe is really the odd duck when it comes to pipe size since even at schedule 80 it's ID is almost a 1/4" in diameter. The number of threads is the easiest (for me) to tell the difference 1/8 and 1/4 inch pipe, 27 vs 18.

Ok, so much for the hot air I am blowing today.:)


American National Standard Pipe Threads
NPT: National Pipe Taper Thread A sealant compound or Teflon tape must be used for a leak-free seal.
FPT: female (internal) National Pipe Taper threads
MPT: male (external) National Pipe Taper threads
NPTF: Dryseal American National Standard Taper Pipe Thread No sealant is needed for a seal.
NPS: American Standard Straight Pipe Thread Used for mechanical joining -- holding a fitting in place. An O-ring or a metal seal is required.
NPSF
: Dryseal American National Standard Straight Pipe Thread
British Standard Pipe Thread
BSPT: British Standard Pipe Taper threads
BSPP: British Standard Pipe Parallel (straight) threads​
 
So Vance, why do you think google did not find IPS? Can you show me a query that will get that? A discussion on the Home Machinist board opined that it meant Iron Pipe Straight. Are your responses always so helpful or did you just pick me on a bad night?

If it is so straightforward why don't you post a link to the definition of IPS?

Thanks for very little other than entertainment.
-Art

Your question was, "Okay, but if 1/8 means 1/8" what does this refer to?...Can you help or point me to an explanation?"

I thought you were intelligent or interested enough to follow my suggestion and Google "pipe size" in order to answer your question. Sorry I was wrong.

I took the time to try it myself and found the first hit contained more than most people would want to know about pipe size:
http://en.wikipedia.org/wiki/Nominal_Pipe_Size

Larry
 
Condescending reply, ignorance of the subject, and poor spelling!

"I" = internal?
P = pipe - but you prolly already got there eh?
S = strait

Your serious? You never used pipe fittings before? Pipe sizes are sized for the internal bore of the pipe, although in many of the smaller cases (especially 1/8") the bore is off nominal by quite a margin.

W/O looking - yes - 1/8NPS is likely a letter S. (National Pipe Strait.)

Also - 1/8 pipe is 27 TPI.

While it is great that the local hdwr was able to help you out like this - you can save yourself many future haertaches (attacks?) by NOT buying hdwr quality cutting toys! And I kant stress this nearly enough when it comes to TAPS! They can be used succesfully in thread repair - but not for cutting new. (Your milage may vary.)
------------
Think Snow Eh!
Ox

People come to these forums looking for information, not criticism. It was pretty obvious the person you critiqued was talking about straight threaded lamp fittings, NOT the tapered pipe fittings commonly used to seal gases and liquids. Yet you proceeded to ridicule him for being ignorant of pipe threads!

Your post is loaded with grammatical and spelling mistakes. I counted no less than 10 of them. Maybe you should learn to write before dispensing criticism.
 
People come to these forums looking for information, not criticism. It was pretty obvious the person you critiqued was talking about straight threaded lamp fittings, NOT the tapered pipe fittings commonly used to seal gases and liquids. Yet you proceeded to ridicule him for being ignorant of pipe threads!

Your post is loaded with grammatical and spelling mistakes. I counted no less than 10 of them. Maybe you should learn to write before dispensing criticism.


Those mistakes are endearing................:stirthepot:
 
People come to these forums looking for information, not criticism. It was pretty obvious the person you critiqued was talking about straight threaded lamp fittings, NOT the tapered pipe fittings commonly used to seal gases and liquids. Yet you proceeded to ridicule him for being ignorant of pipe threads!

Your post is loaded with grammatical and spelling mistakes. I counted no less than 10 of them. Maybe you should learn to write before dispensing criticism.

A lot a lazy f*cks come to this forum too. They have a question or problem and instead of attempting to search the answer out, they register here and expect the members to spoon feed them the information.

As far as any spelling errors incurred by Ox, the knowledge and experience he brings, outweighs your good grammar and spelling. Not everybody has IeSpell (or similar) loaded on their PC.
 
People come to these forums looking for information, not criticism. It was pretty obvious the person you critiqued was talking about straight threaded lamp fittings, NOT the tapered pipe fittings commonly used to seal gases and liquids. Yet you proceeded to ridicule him for being ignorant of pipe threads!

Your post is loaded with grammatical and spelling mistakes. I counted no less than 10 of them. Maybe you should learn to write before dispensing criticism.

Talk about condescending and ignorance, you with your 6 posts come in here and rip up somebody with 13,000+ posts? I'm guessing from your screen name you spend all day pushing paper and are only critiqued on what clueless superior paper pushers can find as faults. Then there are people like OX that spend all day with their hands dirty actually doing stuff. They don't have the time or inclination to spell check or toe the current line on political correctness. Your type run to them when your ass is in a jam because you know they can bail you out, but you won't give them the time of day otherwise.
 
Well now....

FWIW - I saw this thread pop to the top and saw that I has replied to it once upon a time, so I checked it out to see...

I read my reply and thought that sounded a bit harsh. Not sure why I did that. ???

And then to find that the only reason that a 3 year old thread had surfaced was to bitch at me about it?



EDIT:

After re-reading my reply a cpl more times - trying to figger out why I werded it that way, I don't think I meant it in nearly a condecsending way as it appears. I think I must have been more in shock as to think that someone on a machine shop forum would not be familier with the 1/8" pipe designation?

I don't know - just guessing as I didn't use any emoticons that day - I kant be sure anymore either.
:o


------------------------

My speling and gramor aint neccessarilly dun in error BTW.
 
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People come to these forums looking for information, not criticism. It was pretty obvious the person you critiqued was talking about straight threaded lamp fittings, NOT the tapered pipe fittings commonly used to seal gases and liquids. Yet you proceeded to ridicule him for being ignorant of pipe threads!

Your post is loaded with grammatical and spelling mistakes. I counted no less than 10 of them. Maybe you should learn to write before dispensing criticism.

Geesh. Are you really going to dig up a 3 year old thread to point that out? So, your contribution to a "machining" related forum is to point out spelling and grammatical errors? This isn't English class. And, I always found that OX's posts commonly have similar such errors, such as "skewl", "werk", etc., but I have always read them to be his personality. At least he threw in an extra tip, suggesting to not buy tools from a hardware store, especially taps. Years ago, in a pinch, I bought a 1/4" NPT tap from a hardware store and it was worthless, almost as if the sharps were broken.

With groing use of the internet, I began to see how common it is to find mispellings and improper grammar. It doesn't mean I critisized anyone about it though. If you want to make a real gripe, complain about spell checkers, cell phones and texting, etc., as they are making younger generation dumb as hell on that subject. And I have seen stupid errors on formal documents, where they most of all should not be
 
Well now....

FWIW - I saw this thread pop to the top and saw that I has replied to it once upon a time, so I checked it out to see...

I read my reply and thought that sounded a bit harsh. Not sure why I did that. ???

And then to find that the only reason that a 3 year old thread had surfaced was to bitch at me about it?


------------------------

My speling and gramor aint neccessarilly dun in error BTW.

Oh yeah, well I fer won am apauled at yer spelink!
 
This'll surprise those that know me but I'm going to give a short civil answer :)

The diameter on a pipe thread refers to the approximate hole diameter of the pipe. It's the hole diameter on a pipe that's important so that's the diameter that's used when specifying a pipe thread. The pipe OD will depend on the pipe wall thickness and must sometimes be turned to size.

Gordon



Actually - for most common sizes and schedules, the OD's remain the same, and the ID's change with the wall thickness. But yes, the "sizes" are relative to the bore, although 1/8 pipe has always seemed to me to be far from 1/8" bore. (shrug)

It seems that pipe starts to use OD size referance @ 14" for some reason tho. ???


--------------------

I am Ox and I approve this h'yah post!
 
Art,
Electrical connections are not in the same class as anything in the machinery handbook. As long as it holds the lamp up, you're good.
Non illegitimus carborundum.
have fun
i_r_
 








 
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