Pipe - Tube difference

What is the difference? I have purchased manual for building mini chopper frame, and I have no idea what to ask for in shop (where I am no one in metal shop - or any other speaks English). English is not my native language, so please go easy.

And what is the difference when bending pipe and bending tube. I knew that bending tools are different, but why? Something to do with a diameter?

Reply to
Yvan
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Pipe is usually larger than the claimed dimension: 1/2" pipe is closer to

3/4" in diameter. There are tables. Tubing, on the other hand, is done to even values, 2" tubing is either 2" inside or out. It also may have thinner wall, depending on the use of "tubing".

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

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Reply to
Tim Williams

Pipe is measured by it's internal diameter, and is not usually very precise. Regardless of the schedule, the outside diameter remains constant (at least in theory). When the schedule of the pipe changes, the wall gets thicker or thinner, so the size of the hole in the pipe changes.

That rule applies to pipe up to 12". Once pipe goes above that size, it is measured by the actual outside diameter, meaning 14" pipe OD measures 14", unlike 12" pipe, which measures 12-3/4".

Tubing is measured by the outside diameter. When you buy tubing, you specify the wall thickness and the outside diameter. That would be the equivalent of specifying schedule when buying pipe.

The advantage of tubing over pipe is that it is made in a much wider variety of sizes. Pipe is restricted, and the larger it gets, the larger is the restriction. Still, each of them have a purpose that they serve well.

I'm not well versed on pipe or tube bending, but they bend similar to one another. Your comments on diameter are close to the problem-----if you expect good bends. The shoes that support the material must be a proper fit to prevent kinking or otherwise distorting the material at hand while bending. Perhaps someone with bending experience will chime in and provide more details.

Hope this helps

Harold

the tools used must fit the material at hand.

Reply to
Harold & Susan Vordos

Reply to
Waynemak

This was explained well to me, by a plumber - that the imporant thing about "pipe" is what's flowing *inside* of it, so the ID that counts.

Four inch cast iron pipe is just about the right size for...

Yep!

Jim

Reply to
jim rozen

--Wall thickness is one difference; the other is the amount of tooling that's available to work with it: tons of pipe benders, for instance, but tube benders that won't kink the material are rare and expensive.

Reply to
steamer

That has nothing to do with what distinguishes tubing from pipe. Tubing comes seamless, drawn over a mandrel, drawn over a mandrel- special smooth ID, cold drawn butt welded and electric resistance welded. Some of these descriptions match pipe perfectly.

It's the size of the material that determines what it is, not the method by which it is manufactured. Both tubing and pipe are available in steel, stainless steel and aluminum, too.

Harold

Reply to
Harold & Susan Vordos

So Harold,

A piece of tubing with the same dimensions, made by the same method, made from the same material is functionaly the same as a piece of pipe made the same way? How does one get identified as "pipe" and the other as "tubing". Is it purely how the two are measured and how their dimensions are represented? Why would these be labeled differently? Is one commonly available in one form that the other is not?

Puzzled,

Peter

Peter

Reply to
Peter Grey

"Pipe" is just an arbitrary term from blacksmith days. Over time, pipe sizes were standardized with arbitrary specifications, which are listed in tables compiled by the industries and government. Even the inside diameter has little to do with the "nominal" sizes. "Tube" to most people is anything that looks tubular and is specified in size by the "outer diameter"

Reply to
bw

Like I said, pipe comes in odd sizes, typically somewhat larger than the number. "1/2 inch" pipe is more like 3/4" in diameter, depending on where you measure it.

Simply put: to find the actual diameter, pipe needs a table. Tubing doesn't.

Here's a good one (though crappily written with FrontPage* - it might take a while to download!):

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(*I would happen to know this, because I ran through the entire table and culled all the extraneous formatting crap... shit, when I finished it was

7kB!)

Tim

-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @

formatting link

Reply to
Tim Williams

Pipe is measured as "nominal bore" which means that the size quoted is an approximate inside diameter. for instance 1/2 NB is about half an inch inside diameter and the wall thickness is specified either as a "schedule 5 or 20 etc . Tubing is measured as an outside diameter and a wall thickness. As a general rule tubing has a better finish and more consistent diameter than pipe.

Tom

Reply to
Tom Miller

nothing

In sizes up to 3/4" pipe, there are no identical matches of sizes with tubing, so pipe is unique. At 1", pipe is designated as 1.315" OD. There are several listings of tubing with identical, or very close, sizes when compared to various schedules of pipe. With that in mind, unless the piece in question is marked, or you have certs, it's possible you can't discern one from the other. For example:

ASTM A 53 Grade A and Grade B, ASME Boiler and Pressure Vessel Code Specifications SA 53, Grade B (seamless or welded type E)

Should you encounter a piece that is either welded or seamless, and the dimensions match both tubing and pipe, without markings there may not be a way to tell. I'm not sure it matters unless the pipe/tubing must meet certain requirements (as above). Back to the certified material!

Harold

Reply to
Harold & Susan Vordos

Reply to
Glenn

Square tubing is nothing but round tubing that was run through a "turkshead" roller (4 rollers set at an angle to the tube) Start with round, comes out square (with rounded corners)

You can buy tubing made to tubing specs (A513 types 1, 2, and 5) in pipe sizes (OD is the odd pipe sizes)

Sure you can thread tubing, you can thread it to tapered pipe threads, any of the standard SAE threads, or to any weird special thread you want. Go ask the telescope makers what thread pitch they use!

C> How bout this for a kicker?? I have heard of square tubing but neve heard

Reply to
RoyJ

Since I'm a spec writer, I find it amusing as hell....

Reply to
Fuhh

Nedavno Tim Williams pise:

What about tube material? I want to make some mini chopper frame. What tube material should I look for (that bends most trouble-free)?

Reply to
me

Pipe (like water pipe) is measured by it's ID (inner diameter) and tubing by it's OD.(outer diameter)

I have fabricated lots of mini bike frames and have mostly use 1" mild steel tubing with a .058 to .125 wall thickness.

The thicker the wall the less likely for the tubing to crimp. but the frame will get heavy pretty quick with real thick tubing.

Check out Pro Tools on the web. they have a good hobby priced bender, the

105 model is what have, real nice people to deal with. located in Florida I think.

Good luck.

Reply to
Tweakit

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