reverse pipe thread nipples

Ken_40

a machinist's hanbook from the 1940's every whacko thread on earth is in there.

Brit, Whitworth, etc.

Need the pitch (tops of the thread/rigids per inch or foot, taper or straight, and diameter of the stock if any is unthreaded. If a "close" nipp, the o.d. of the first full thread, and, the last - as well as the length of the entire thread revealed on one side.

I may have an answer tonight of our Valentine's Day dinner oiut is scrubbed by the foot-an-a-half of blowing snow keeps up getting worse; we're not celebrating anything.

Pat_25

reverse pipe thread nipples for a US radiator

Does anyone know if the pipe thread in a 5 tube radiator (probably post 1935) is british standard pipe or US thread? I had one of my rads freeze and 2 sections need to be taken out. I started taking it apart, even found the reverse threaded 1 1/4 nipples, but they are BSP, not US. How can I tell what style thread I have?

Pat_25

What i found

Well, I contacted this company in Canada who sells old radiators & assembles them. They said all rads in this country are on US thread. Also, I tried a 1 1/4 nipple and it is too small so it must be 1 1/2? Does anyone know where I can get reverse thread nipples for old rads? I have searched and searched but can't seem to locate anyone who sells them, except of course this Canadaian company who wants $26/nipple and $5 per gasket. (!!!!)

Ken_40

Perhaps it's time to...

cut your losses.

You've entered the land of esoteria. Your best bet would to simply search around for a replacement rad, fawgettabowt "rebuilding" what you have. One section too large or one too short would make a nominal difference.

If you are unfamiliar with the difference (by eye) of a 1-1/4" vs. 1-1/2" nipp., there are other issues you should address, namely: "How much of a challenge are you up for"?

Most pros use the index and middle finger trick if the eye cannot distinguish between 1-1/4 and 1-1/2 nipp size. If both fingers can only be forced in to the first digit - and even that's a tight fit; it's 1-1/4" pipe. If both fingers slide in relatively easily to at least the second joint, it's 1-1/2"

I think you already know what needs to be done(;-o)

Pat_25

The money

Believe me I have thought this through. i have gotten 3 sections off the rad by using a recip. saw because 1) a replacement is >$1400; 2) none I have found are as nice as the one i have. It is 54" long, 5 tube; I figured it was worth a try to fix it, if I could just find the reverse threaded nipples. Per your trick it is definitely a 1 1/2". I can't believe no one makes these! The rad is less than 100 years old, you would think someone carries this part. Any ideas? I am not willing to spend the $$ for the ones from Canada, because it may leak when i reassemble so I am not throwing away that kind of $$. There are 11 threads per inch so I believe that makes it US.

Ron Gillen

No Canadian Pipe Threads

North America uses national pipe threads NPT. Much of Europe uses British standard pipe threads. NPT 1 1/2" threads have 11 1/2 threads per inch and the angle between the flanks is 60 degrees. BSPT 1 1/2" threads have 11 threads per inch and the angle between the flanks is 55 degrees. You can't tell the difference by lookin. You need a left/right nipple so one side of your female threads is a right hand thread. If they are clean you should be able to thread an 1 1/2" NPT nipple in a couple of turns by hand. If they are full of rust you may need to run a tap in first. An 1 1/2" BSPT nipples won't go in a full turn by hand. My point is that there are no Canadian pipe threads

Ken_40

Pat,

Find somebody with a small machines shop, a lathe and the correct "formula" for both NPT and "reverse" NPT.

There used to be a place in Garwood NJ called Garwood Nipple Works. If they're stil in business, they may have made the ones your cutting out.

Then too, you might consider having the threads broached and covert the rad to push nipps?

Unknown

I have

a pretty good assortment of L/R nipples up to 1.25", rarely do I need 1.5", I can get them though, but if you don`t want to spend the money, hey, what can I tell ya? Leaks on L/R nipples are a chance we all take.

Dave

Pat_25

Hey

It's not that I don't want to spend any $$ but I need 20 of them, so at $26/nipple it is cost prohibitive. I am going to try the idea below with a 1 1/2 nipple to see if it is NPT; you said you seldom need a 1 1/2, usually 1 1/4? I tried a 1 1/4 nipple NPT and it was too small. BTW, do you fix these type of rads? Also the idea of grinding out the threads and using push nipples is great, except i have no where is run a threaded rod to hold it together!
Pat

Pat_25

Thanks

Thanks Ron. I will try that to see whether it is NPT or BSP. BTW - I know there is no Canadian pipe threads but the company up there told me all Canadian and US rads are usually NPT, not BSP. I was hoping someone who did this all the time would be able to tell me.
Pat

tim smith

Who is the company in canada

Pat_25

Thanks

Thanks Ken. I did start calling machine shops in my area and there is one who will look at it. May be the best option, but I will also call the one in Garfield to see if they have it already.
Pat

Pat_25

company

Shafter Brothers out of Montreal

Unknown

There are a few

1.5 LH tapped rads out there, but on second thought are you looking for those old nipples that go between the "sections", those little stubby ones with the "grabbers" on the inside?, or the supply and return to the rad?

Dave

Pat_25

you got it

Yep it is the reverse thread (half right thread/half left thread) nipple that goes between the sections to hold them together. The ends are 1 1/4 NPT which are easy to find, it is just a straight nipple.
Pat

Unknown

Oh Man,

sorry Pat, I thought you meant the others. I have not seen those "old" nipples in years, besides if you do find them you will need a special tool to assemble them, not a job I would envy for sure! If I were you, I would start checking scrap metal dealers for another rad. They really were a "special" nipple, not tapered pipe thread as they "drew" the sections together.

Dave

Pat_25

I know

I hear ya. They actually go together with a regular spud tool. I am going to keep hunting (it can't hurt). I have also been looking for a "used" rad but so far, haven't found anything decent for less than $1300 (with shipping). Figure I will have to call these guys monthly until my rad shows up in order to find the right one. So, currently I have flex pipe and a galvanized piece of pipe joining the two ends.

Pat

Unknown

A spud tool?

that`s a new-one on me. The only ones I have ever seen needed a long bar configured to the "grabbers" on the inside of the nipples, this was inserted through the plugged holes. You`ve got me really curious now, can you post a pic so we can see what you have?

Dave

Pat_25

The spud wrench i have is a silver multi-sized wrench that will turn the rabbit ears inside the rad fins. Of course, you have to remove each one to get to the bad ones, but since everything is totally corroded together anyway,there is no way to just unthread the bad sections but leave the good sections connected. Because I have to remove each section back to the back ones, when i reassemble, I can use the spud wrench to tight the nipples. I did take the end bolt off so it fits in the space. I do know what tool you are talking about. Burnham boilers sells one for about $600. (!!)

Pat

Unknown

Pat,

I`ll say it once again, Oh Man!!! Good Luck.

Dave

Unknown

Hey Pat

just had an idea here, could you not take a piece if 1.5" pipe and run a continuous thread on-it to get past the tapered part of the die?, then bandsaw them off to the length you need? One side will be right, and the other left then. But I don`t know how you would get the "grabbers" inside to hold your tool. In the "old-days" we used to make up nipple-chucks like this out of "turned" couplings. Just a thought!

Dave

Ron Gillen

Sorry Dave

If you cut a running thread and saw it off, the other end will still be right hand. Think all thread rod.

Unknown

Your right Ron,

where was my head? That idea wasn`t even worth 2 cents. Been a long day, sorry Pat! (Kinda like figuring fan blades vs motor rotation when your tired!) LOL.

Dave

Pat_25

Latest

Well, i found a company to make me some of these. No prices as of yet. i may decide to do some supply, internet sales, etc. Since someone else must have gone through this!
Pat

Rob_25

RH-LH Nipples

http://www.mcmaster.com/

Mcmaster Carr is a catalog I order from regularly. Page 41 of their catalog lists nipples with RH one end and LH the other end. I'm not sure what size you need, but I didn't see 1 1/4" NPT listed.

Rob