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Author Topic: ENGINEERING QUESTION !  (Read 2259 times)

supersonic

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ENGINEERING QUESTION !
« on: November 25, 2007, 12:38:13 PM »

When does a wire become thick enough to be a rod ? and when does a rod become thick enough to be a bar ?
FOOD FOR THOUGHT   ???

Dave.
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Colin Bishop

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Re: ENGINEERING QUESTION !
« Reply #1 on: November 25, 2007, 12:54:19 PM »

And when does a bar become a girder?
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wombat

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Re: ENGINEERING QUESTION !
« Reply #2 on: November 25, 2007, 12:56:39 PM »

Isn't the difference more to do with the method of manufacture?

Wire is drawn - having spent many an unhappy hour in wire drawing millls, it is an impressive sight.

The definition of bar and rod is perhaps less clear, they both seem to be rolled. The only distinction I have found suggested is that there is more control over the material composition and dimensional accuracy in bar than there is in rod
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Bunkerbarge

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Re: ENGINEERING QUESTION !
« Reply #3 on: November 25, 2007, 01:15:12 PM »

And when does a bar become a girder?

Have you ever tried getting a drink out of a girder?
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chingdevil

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Re: ENGINEERING QUESTION !
« Reply #4 on: November 25, 2007, 01:18:34 PM »

My definition is
Wire is drawn from a rod, as wombat said very impressive to watch. A girder is rolled from an ingot of material. A rod usually relates to a round section of material while a bar usually relates to material with a flat section like a square or a rectangle ie 8mm by 3mm flat bar.

Most material is rolled or drawn from the original ingot, if it is drawn it goes through dies getting smaller at each pass. If it is rolled it goes through rollers to get its profile. Most round profile material will have been drawn, you can usually see the marks on the outside made by the dies. If the profile of the material is many faceted like hex shape that will be drawn also.

Brian
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funtimefrankie

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Re: ENGINEERING QUESTION !
« Reply #5 on: November 25, 2007, 01:31:23 PM »

Does sheet become plate?
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Bunkerbarge

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Re: ENGINEERING QUESTION !
« Reply #6 on: November 25, 2007, 01:53:53 PM »

I think the whole question is slap bang in the middle of one of those wonderfull grey areas that have clouded over with the passage of time.  What maybe initially started of as a definition years ago has been blended in with years of abuse of the language until all the distinctions are lost.

That's how the language develops anyway but uit is sometimes interesting to revisit the roots of a words and see just where it originally came from.

I am sure there will be many different ideas surrounding these such as wire ceases to be wire when it it no longer flexible etc...etc...

I think I'll get my engineering almanac out and see what it says!!
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Bunkerbarge

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Re: ENGINEERING QUESTION !
« Reply #7 on: November 25, 2007, 01:57:59 PM »

My definition is
Wire is drawn from a rod, as wombat said very impressive to watch. A girder is rolled from an ingot of material. A rod usually relates to a round section of material while a bar usually relates to material with a flat section like a square or a rectangle ie 8mm by 3mm flat bar.

Most material is rolled or drawn from the original ingot, if it is drawn it goes through dies getting smaller at each pass. If it is rolled it goes through rollers to get its profile. Most round profile material will have been drawn, you can usually see the marks on the outside made by the dies. If the profile of the material is many faceted like hex shape that will be drawn also.

Brian


I actually had a very similar discussion with one of our electruical engineers recently and I tend to agree that "Rod" is only round but "Bar" is anything.  We order "Bar stock" of various sections but that also includes round bar and we will refer to it as "Flat Bar", "Round Bar", "Hex Bar" etc..
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supersonic

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Re: ENGINEERING QUESTION !
« Reply #8 on: November 25, 2007, 02:39:52 PM »

Funtime, You beat me to it . That was my next question :-X
 
Dave.
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dougal99

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Re: ENGINEERING QUESTION !
« Reply #9 on: November 25, 2007, 04:18:43 PM »

Does sheet become plate?

Surely it depends on what restaurant/canteen you eat in  {-)





Sorry. In my defence I do cryptic crosswords  :embarrassed:
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BarryM

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Re: ENGINEERING QUESTION !
« Reply #10 on: November 25, 2007, 05:04:10 PM »



Have you ever tried getting a drink out of a girder?
[/quote]

Yep - Barr's Irn Bru is made from them.
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malcolmfrary

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Re: ENGINEERING QUESTION !
« Reply #11 on: November 25, 2007, 05:08:50 PM »

For me, wire is round, metal and bendy, needing support to keep it straight, rod is round and fairly rigid and self supporting to an extent, bar is rod of any other shape.  Tube is rod with a hole up the middle.
Sheet and plate I leave to the caterers.
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Bunkerbarge

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Re: ENGINEERING QUESTION !
« Reply #12 on: November 25, 2007, 06:18:35 PM »

For me, wire is round, metal and bendy, needing support to keep it straight, rod is round and fairly rigid and self supporting to an extent, bar is rod of any other shape.  Tube is rod with a hole up the middle.
Sheet and plate I leave to the caterers.

So how do we get "Round Bar" ?  ::)
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sheerline

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Re: ENGINEERING QUESTION !
« Reply #13 on: November 25, 2007, 10:05:29 PM »

Hang on a minute chaps, perhaps this wire, rod, bar thing has to do with the application it is used for . For example, I can buy brass wire and it stays as a piece of wire (3mtrs) but when I chop of a short pice, and the application is to produce short RODS for lets say a tiny steam engine or such like. A STRIP of 3/16 inch by 1/4inch wide brass then becomes some form of tie bar or ROD.
 I could buy 1/4 inch rod and it would be called that whilst it is relatively short, lets say one metre but if it was half a mile long, it would probably be called a wire!
I dunno, I'm confused but I think we probably call these things the names we do cos we can get them on the bench in the workshop. If our worksops were as big as the sheds at Cardington, we might refer to them as something else. :D
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supersonic

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Re: ENGINEERING QUESTION !
« Reply #14 on: November 25, 2007, 10:14:16 PM »

WIRE WE AT THIS BAR , ROD ? {-) {-) {-) {-)
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sheerline

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Re: ENGINEERING QUESTION !
« Reply #15 on: November 25, 2007, 10:17:21 PM »

Dunno but can the blonde at the the end of the bar gird'er loins?? :o
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supersonic

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Re: ENGINEERING QUESTION !
« Reply #16 on: November 25, 2007, 10:23:48 PM »

 O0
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malcolmfrary

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Re: ENGINEERING QUESTION !
« Reply #17 on: November 25, 2007, 10:54:50 PM »

Quote
So how do we get "Round Bar" ? 

We dont.  Its rod.  Unless the storeman doesn't understand "rod", in which case its round bar.
Again, for our purposes, it could come down to what we use it for.  I tend to think of wire as metal string, rod is a thicker, more rigid version, suitable for pushing as well as pulling, and bar would be something that I would file or cut bits off to make something else.  If I had a lathe, bar would be a candidate for a ride on it rather than rod. 
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Bee

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Re: ENGINEERING QUESTION !
« Reply #18 on: November 26, 2007, 09:46:04 PM »

oh dear, now you've introduced string and rope and hawser and cord and cable.
Now, would you barr and engine over with a bar or a rod? The engine house might have a bar ended rod if the flywheel has slots instead of holes.

Is 're-bar' just American slang for reinforcing rods?

well, gotta go. I have some planks to put in stick to season.
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sheerline

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Re: ENGINEERING QUESTION !
« Reply #19 on: November 27, 2007, 12:14:54 AM »

If you took a load of 1/4inch steel 'rod' in quarter mile lengths, twisted them together and slung them on  pylons to carry electricity, they would be referred to as wires.. or perhaps cables. I think it all comes down to the scale of use and the application it's put to how we name these things..yes/no. Is there really any definitive answer on this... perhaps not but I guess to get the real everyday definition you must look to the metal stockists or materials manufacturers for the real answer .
Interesting conversation this.
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Bunkerbarge

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Re: ENGINEERING QUESTION !
« Reply #20 on: November 27, 2007, 12:57:34 AM »

Looking at a couple of definitions it would appear that the purpose to which the item is to be put is relevent.

For instance a metal bar derives it name from the fact that it is used to prevent passage of something i.e. "To bar" as here:

1. a relatively long, evenly shaped piece of some solid substance, as metal or wood, used as a guard or obstruction or for some mechanical purpose: the bars of a cage. 
2. an oblong piece of any solid material: a bar of soap; a candy bar. 
3. the amount of material in a bar. 
4. an ingot, lump, or wedge of gold or silver. 
5. a long ridge of sand, gravel, or other material near or slightly above the surface of the water at or near the mouth of a river or harbor entrance, often constituting an obstruction to navigation. 
6. anything that obstructs, hinders, or impedes; obstacle; barrier: a bar to important legislation. 


This has now obviously evolved into relating to most cross sectioned lengths of material be it round, square, flat, hex etc..etc..


However this is one definition that I found for a "Rod":

Metallurgy. round metal stock for drawing and cutting into slender bars.

This would tend to indicate that bars must be flat and rod is round, square, hex etc.


And there again we order all our metal stock as "Bar Stock" whatever the cross section be it flat (Flat Bar) or round (Round Bar)

At the end of the day is there a right and a wrong?

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bigH

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Re: ENGINEERING QUESTION !
« Reply #21 on: November 27, 2007, 03:50:18 PM »

  Will that be a drink all ROUND and we'll SQUARE up on saturday ??????
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Roger in France

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Re: ENGINEERING QUESTION !
« Reply #22 on: November 28, 2007, 07:29:39 AM »

Many folk think a comprehensive spec. for anything is pedantic. They often quote the famous example of a judge asking "What is a boot?" as an example of silly questions. In fact, checking that we all agree on what we are actually talking about or specifying can be very important.

I was once told of the illustration which is close to this original Thread: in the first Communist 5 Year Plan steel producers were called upon to produce X tons of steel. They did, but in ingots of such a size that it was difficult to machine them. In the next 5 Year Plan they were told to produce X square metres. They did, but it was so thin as to be difficult to handle.

Roger in France.
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Captain Povey

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Re: ENGINEERING QUESTION !
« Reply #23 on: November 28, 2007, 10:48:20 AM »

Hi All, As I read this interesting thread I started to form an opinion and then got to Sheerline's comments which I think does it for me. Cheers Graham
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