# Hands up if you think flat bar should be flat



## 2volts (Feb 27, 2017)

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.




I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.




Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544


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## Kiwi (Feb 27, 2017)

is it all like that i've seen it like that at the ends of a length


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## 2volts (Feb 27, 2017)

yes. whole 2m. also looked at some stock at the store today and it was the same.


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## cvairwerks (Feb 27, 2017)

Just depends on your definition of "flat"


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## Firestopper (Feb 27, 2017)

If you want "flat" flat bar, you might start off with cold rolled (CR). CR will also be correct in size unlike hot rolled that varies a bit in dimensions.


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## ewkearns (Feb 27, 2017)

I agree with the other posters, but I have to say that stuff is junk. Any machine shop denizen, tasked with purchasing duties, will have their own particular set of horror stories.... especially with export materials produced in some countries.

Maybe a new thread on "_the best places to obtain materials_?"


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## Cobra (Feb 27, 2017)

I have often received the same form of flat bar in Canada when buying those small sizes.  It is usually fine for projects that I am welding up frames etc.  I am with Paco, if you need mostly flat, use cold rolled, if you need flat flat use precision ground stock.


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## RJSakowski (Feb 27, 2017)

It has been my observation that for HR bar, flat is used as a descriptor to distinguish from squares or rounds.  HR is mainly used for welding fabrication where precision is not required.  Given the nature of its manufacture, it is not realistic to expect a precision surface.  i.e., don't expect dimensional accuracy, flatness, squareness, roundness,or straightness from a piece of HR steel.


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## sgisler (Feb 27, 2017)

Looks like what you have there is sheared flat bar, actually sheared from plate or sheet. Very common in stainless 'flat bar'. Hot rolled flat bar is pretty flat across its width and has somewhat rounded edges (variable with thickness; thicker bars have flatter edges). As others mentioned, if you want good size, good square edges, sharp corners in steel, get CRS. True HRS would be next step down in cost/quality. Sheared bar generally at the bottom of the scale of cost/quality. Bonus with CRS is no 'bark' or scale, it's nice and smooth. 


Stan
Sent from my iPhone using Tapatalk


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## kvt (Feb 27, 2017)

Agree with Stan   That looks like sheared stuff.   Find that stuff in places like Lowes and Home depot around here.   there are a couple of steel suppliers that sell the good stuff and often at a better price per foot than you pay the box stores.   But they are not as handy at times.


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## dennys502 (Feb 27, 2017)

That looks like it was slit from a coil. 
If it were sheared the square edges would not be on the same side unless they flipped the sheet over for the next cut. 
A slitter makes both edges the same.


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## 2volts (Feb 28, 2017)

You get what you pay for I suppose. 

It's a sign of the general decline in quality when most consumers are happy to buy on price alone. 

I wasn't expecting a geometrically accurate cross section and dimensions but I did expect better than that.

For what I was using it for it didn't matter, but I know next time it's something else to look out for.

Thanks for the replies

pete


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## mws (Feb 28, 2017)

I've seen a lot of flat stock curl like that when it's not quarter sawn from the tree.  
Seriously though, I almost never use that Chinese steel (or aluminum) from the "Big Box" hardware. It's all gummy and full of irregularities. I can't imagine what's in some of it.  I have gotten some good metal from the smaller hardware chains and industrial and marine suppliers.  If I'm not in a hurry though, mail order seems to be the best way to get what you want.


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## willthedancer (Feb 28, 2017)

That stuff in the photo is sheared from MS, which means merchant stock (not mild steel).  The shear was not setup or maintained either.

Sent from my Moto G Play using Tapatalk


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## JohnnieZ (Mar 4, 2017)

I have a question, since I am working with flat bar aluminum alloy. I have a project where I need to bend a 45" length aluminum flat bar into a U shape. That is not too hard to do, though I don't as yet have the equipment to so, but the hard part is knowing whether or not I can bend the flat bar upward at the bottom of the U shape. In other words, bending the material in a vertical direction instead of a horizontal direction without misshaping it where the bend is. Hoping I don't have to create a mold for my design.

I suppose that I could get a torch, heat the material up and try to bend it to the 70 degree angle that's required, but I'm thinking that I may run into trouble. Any thoughts from anyone here would be appreciated. I am Ziggyboy. I invented the Ziggyboy bullet valve stem cover for bicycles. My question here of course concerns my design for a new type of bicycle wheelie bar for bicycles (muscle bikes) that I'm working on. I collect vintage Schwinn Stingray bicycles, that's how I ended up getting involved with the whole muscle bike and chopper bicycles scene.

Thanks, Ziggy.


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## dennys502 (Mar 4, 2017)

A little more info would be helpful. Material thickness and width. Radius of the bend.

Are you talking about bending it on edge like this?



Denny


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## JohnnieZ (Mar 4, 2017)

Thanks, Denny. Sorry, I didn't intend on leaving out that info.

The aluminum bar is 1/4 inch thick and 3/4's of an inch wide.  Your diagram is the opposite of what I am doing. Here is a picture of my patented prototype I'm working on. The bottom bar of this wheelie bar is what I am referring to. The trouble I think I've run into is getting the duck bill part of the bar that is just beyond the wheels to bend upward enough on the end. About a seventy degree angle is what I need, so that the skate board wheels touch the ground before the end of the bar does. Can't have that part of the bar scraping the street, if you know what I mean.

I managed to bend it upward a bit, but that's not far enough, as I found out when I mounted the wheelie bar on my bike. Do you think I'll be able to accomplish that much of a bend without distorting the metal? I'm in the process of finding a builder for this project, just haven't gotten there yet.

Thanks for your reply. Hope we can both learn something about this sort of thing.

Ziggy


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## dennys502 (Mar 4, 2017)

You could clamp it to a bench with a piece of wood and a couple of c clamps. Bend the U bend first.
Slip a pipe over the aluminum to bend it.
This would work for a prototype. The holes would have to be put in afterwards where the bend is.
I've got a 2" radius on the wood in the image.


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## JohnnieZ (Mar 4, 2017)

Gee, thanks, Denny.

The bend you are showing here would be pretty close to the amount of bend I need. Yes, of course I would have to do the bend before drilling the holes, otherwise the material would separate where the holes are, and thanks for your awareness about those sorts of things, I just hope I don't end up with a crack when I try to bend the bar that much. I have heard about, "thermal forming," and I imagine that means, "heat," like heating up the bending area with a torch that would help keep the material from cracking where the bend is, but different or done with machinery. Wish I had bending machinery at my finger tips, but I will have to get those things, just like what I need that's in your diagram. That rounded edge that you put on the top block is exactly what should be used in order to get a more gradual bend instead of a sudden bend. Ingenious on your part, my friend.

I haven't tried bending the bar that much, but I guess I'll find out what needs to be done by simply doing it. Still don't know if it's possible or practical where metal works are concerned. Your diagram is a good example of approach. Only instead of wood, I think maybe two pieces of metal plating would be better to use because of heating up the bar at the bend area. Yeah, the block needs to be about an inch thick, as you have shown here.

So again, thanks, Denny. You have given me new confidence in this project.


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## dennys502 (Mar 4, 2017)

Is that just plain 6061 extruded aluminum? If it is you shouldn't have to heat it to bend it.
 By slipping a piece of pipe over it up to the point where the bend would end it should bend nicely - thats not a very large bend - 20 degrees.

In production it could be formed in a press brake.


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## JohnnieZ (Mar 4, 2017)

Ah, a press brake. I first time I saw one of those was when I was in a industrial sign making shop a long time ago. I have a meeting set up with a man that owns a machine shop. Hopefully, he will be able to work with me. I heard that he has a lot of machinery, so he must have one of those.

I'm not sure if the aluminum is 6061 extruded aluminum, I had a friend who makes sissy bars for muscle bikes make the first prototypes. He can no longer work because of health problems, so this is where I'm at on this idea that I had and hope to make come to fruition. I will of course have to make sure I get the same thing when I buy more material. I'm not a big time machinist, I am learning about metals and such, and am glad I found this site in order to have someone to talk to about it.

I was thinking that I may not have to heat up the aluminum bar, but as you can tell, I've been doing a lot of guessing.

I want to achieve about a seventy degree bend, maybe less, as I bend the first one. I'll need to check if I have enough bend by testing it on the bike. If I need more bend then I'll bend it a few more degrees and make sure there is enough bar clearance away from the ground when the bike is in a wheelie position.

Too bad I don't have you for an employee, Denny. Ha!

I paid for the materials to make the first two prototypes, the one you've seen and the other that is narrower is for bikes without shocks. I also paid the builder for making them. He failed on the bending of the bar at the end, but it's nice having two prototypes to go by. I will be looking for the same deal from a new builder. I tried bending the bar more at the end, but I realized it was a no go with what I had to work with. All I need is the bottom bar and the struts to be made, I can do the rest, like drilling the holes, etc. Although getting the holes drilled as well would be nice. All I have are bike tools for working on bikes. Ha! An inventor or developer without a machine shop, like myself, is like a bicycle with no wheels.

Thanks for showing interest in helping me, Denny. If you are any representation of the people here on this site, then I'm in very good shape.

Ziggy


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## Silverbullet (Mar 4, 2017)

I've often used a diameter of choice for the bend. Then clamp and bend wrap to size , if doing several ill weld a small tube thickness clearance and drop a rod and bend to shape. The rod holds the bend , you can make circles easy .


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## dennys502 (Mar 4, 2017)

You are welcome Ziggy. I'm 68 and retired. I had a small manufacturing company and I did all the design work and tooling. I made a lot of specialty machines to do things that would make it profitable to make things. Most of my products were point of purchase displays. I made thousands of Paint chip displays for General Paint and Chemical (True Value Hardware) and other paint companies. A lot of dental trays and containers for U of M, U of Oklahoma and others. Too many different items to list but that gives you a rough idea.

Denny


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## Silverbullet (Mar 4, 2017)

I've often used a diameter of choice for the bend. Then clamp and bend wrap to size , if doing several ill weld a small tube thickness clearance and drop a rod and bend to shape. The rod holds the bend , you can make circles easy .


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## Okapi (Mar 4, 2017)

firestopper said:


> If you want "flat" flat bar, you might start off with cold rolled (CR). CR will also be correct in size unlike hot rolled that varies a bit in dimensions.



The quality you have is clearly the cheapest one, which you use normally to make garden decorations etc…
Normally the seller does ask you what you want to make with the material, here it's cut iron sheet which is the cheapest possible, the cold rolled cost X times for the same weight, but it's perfect geometrically and sized with the tolerance given by the maker.
You can look on this PDF the large number of possibilities you have fot the same size of steel or iron.


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## JohnnieZ (Mar 4, 2017)

dennys502 said:


> You are welcome Ziggy. I'm 68 and retired. I had a small manufacturing company and I did all the design work and tooling. I made a lot of specialty machines to do things that would make it profitable to make things. Most of my products were point of purchase displays. I made thousands of Paint chip displays for General Paint and Chemical (True Value Hardware) and other paint companies. A lot of dental trays and containers for U of M, U of Oklahoma and others. Too many different items to list but that gives you a rough idea.
> 
> Denny



*Ha! I'm goin' on 63 this year, myself. I find that when people see my Ziggyboy name they think I am a boy. The name is all about keeping a young frame of mind, and my bicycles make doing that easy for me. "Never too old to ride," is my motto. LOL! I ride all kinds of bikes, mountain bikes, etc.

So wow! I see that you have bent enough metal to build a sky scraper, you know your stuff. The creativity is what we have in common, experience, well, that's a different matter. I also see that you are an inventor of sorts. I imagine I have used paint chip displays right off of one you made.

I like to think of myself as an inventor, only none of my inventions have made me any money. I was a backhoe operator and I retired from that as well as I did music. I built chevy cars in my youth and learned that from my dad who was a very good mechanic, welder, etc. So I do the best I can with what knowledge I have while learning more. I enjoy giving to the bike world and want to give something to the bicycle crowd before I leave this Earth. Ever since I was a kid, I loved bikes. I own thirteen bikes. Most of which are vintage Schwinn Stingrays, even the first year, 1963.

Thanks again for giving me some of your knowledge for free. You're a good soul. Hope we can converse about machining more in the future. With all the help I need, I'm sure I'll be back to pester you again. Ha! Ha!

Ziggy*


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## Downunder Bob (Mar 5, 2017)

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.




I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.




Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544


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## Downunder Bob (Mar 9, 2017)

Or if you want precision flat and size get gauge plate, more expensive but you get what you want. should be plenty of steel merchants in Perth, forget bunnings.


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## 2volts (Mar 10, 2017)

I know Bunnings is all about price and convenience but I was just surprised that the quality would be that poor.

When I need good quality I go to a steel merchant such as "The Steel Store" in Kewdale which is Bohler Uddeholm, world wide steel vendors.
Like I did today, to get 2m of 32mm x 20mm 1020 carbon steel bar.
No complaints about that purchase.


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## Rustrp (Mar 10, 2017)

2volts said:


> I know Bunnings is all about price and convenience but I was just surprised that the quality would be that poor.
> 
> When I need good quality I go to a steel merchant such as "The Steel Store" in Kewdale which is Bohler Uddeholm, world wide steel vendors.
> Like I did today, to get 2m of 32mm x 20mm 1020 carbon steel bar.
> No complaints about that purchase.


 
Where you buy is only a small part of the equation. With most product being sourced from all over the world, and brokers purchasing from the mills to supply all the smaller distributors, along with the mills being located in China, India, Pacific Rim, etc. HR quality is always in question. What you have is HR strip run through rolls that are worn out or the flattening rolls were not adjusted. If it were sheared from plate or slit from a coil there would be no crown or the process wouldn't produce a crown. Some stainless bar is sheared but there are straightening methods used after shearing.  The problem with going to CR is that any bending that's close to 90 deg. with a tight radius will result in cracking unless you heat it up because CR is exactly that, rolled to dimension in a cold state. 

 After cutting up 500' of 2" x 2" x .188" tube, I discovered one corner radius was larger than the other three. For esthetic purposes, I had cut the tube so the seam was on the back side with alternating (flipping the tube over) 45 deg. cuts. Grinding, sanding and blending the corners produced many expletives. 

Just think of this as a low budget steel mill (steel processor) buying used equipment to set up their mill, along with employees who have little training on running the operation. These issues add cost to every product produced along with less than acceptable quality. I get verbose on these topics because just about the time a market gets the kinks worked out and the quality improves, the buyers move to the next cheap, cheaper, cheapest, labor market. -Russ.


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## Rustrp (Mar 10, 2017)

JohnnieZ said:


> Gee, thanks, Denny.
> 
> The bend you are showing here would be pretty close to the amount of bend I need. Yes, of course I would have to do the bend before drilling the holes, otherwise the material would separate where the holes are, and thanks for your awareness about those sorts of things, I just hope I don't end up with a crack when I try to bend the bar that much. I have heard about, "thermal forming," and I imagine that means, "heat," like heating up the bending area with a torch that would help keep the material from cracking where the bend is, but different or done with machinery. Wish I had bending machinery at my finger tips, but I will have to get those things, just like what I need that's in your diagram. That rounded edge that you put on the top block is exactly what should be used in order to get a more gradual bend instead of a sudden bend. Ingenious on your part, my friend.
> 
> ...



I see a two step bending process here beyond the prototype. In a short run production set up an H-frame hydraulic press to bend the large radius, and you can make the dies with tube/pipe with reinforcement to prevent them from collapsing. For the hard way bend. a couple of round bars spaced for the bottom die and a single round bar for the top punch/die to press the desired angle (end view would be a triangle pattern). You could also do a similar setup for the large radius by spacing the bottom rounds wides enough to allow the top punch/die to pass through with clearances for the 1/4" bar. You could also drill the holes before forming if you divise a way to clamp the bar when forming the large radius. If you're doing only one or two, denny502's suggestions are spot on. In regard to bending rectangular shapes, the forming operation is referred to as easy way or hard way, which would apply to the amount of stretching or compression required when forming the piece with minimum distortion.


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## chips&more (Mar 10, 2017)

That's special stuff. You should have paid extra for it. You got a bargin!


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## Rustrp (Mar 10, 2017)

chips&more said:


> That's special stuff. You should have paid extra for it. You got a bargin!



I called my supplier and told him the 1/4" x 1 1/2" bar I ordered  was delivered and it was 1 3/4". He said, they don't even make that size. I said, maybe not but I have 300'.


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## Downunder Bob (Mar 10, 2017)

Rustrp said:


> Where you buy is only a small part of the equation. With most product being sourced from all over the world, and brokers purchasing from the mills to supply all the smaller distributors, along with the mills being located in China, India, Pacific Rim, etc. HR quality is always in question. What you have is HR strip run through rolls that are worn out or the flattening rolls were not adjusted. If it were sheared from plate or slit from a coil there would be no crown or the process wouldn't produce a crown. Some stainless bar is sheared but there are straightening methods used after shearing.  The problem with going to CR is that any bending that's close to 90 deg. with a tight radius will result in cracking unless you heat it up because CR is exactly that, rolled to dimension in a cold state.
> 
> After cutting up 500' of 2" x 2" x .188" tube, I discovered one corner radius was larger than the other three. For esthetic purposes, I had cut the tube so the seam was on the back side with alternating (flipping the tube over) 45 deg. cuts. Grinding, sanding and blending the corners produced many expletives.
> 
> Just think of this as a low budget steel mill (steel processor) buying used equipment to set up their mill, along with employees who have little training on running the operation. These issues add cost to every product produced along with less than acceptable quality. I get verbose on these topics because just about the time a market gets the kinks worked out and the quality improves, the buyers move to the next cheap, cheaper, cheapest, labor market. -Russ.



Russ, we have exactly the same problem here in downunder. The government has lost the plot over the last 30 years. they have eliminated all import tariffs and allowed the worst junk from lowest cost makers to flood our markets. Unemployment is high and rising as factory after factory closes down.

We have gone from the lowest unemployment to the highest in the developed world over the last 40 years. We give our resources away at bargain basement prices, and have to import everything, because we no longer have the skills base to make it here. I have had exactly the same problem with square tubing, imported rubbish, it's also full of hard inclusions, we used to make our own.


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## Rustrp (Mar 10, 2017)

bobshobby said:


> Russ, we have exactly the same problem here in downunder. The government has lost the plot over the last 30 years. they have eliminated all import tariffs and allowed the worst junk from lowest cost makers to flood our markets. Unemployment is high and rising as factory after factory closes down.
> 
> We have gone from the lowest unemployment to the highest in the developed world over the last 40 years. We give our resources away at bargain basement prices, and have to import everything, because we no longer have the skills base to make it here. I have had exactly the same problem with square tubing, imported rubbish, it's also full of hard inclusions, we used to make our own.



Ah yes, mill tolerances on tubing. I have older stock/data books from my suppliers that detail the amount of twist from end to end or how close the seam can be located to the corner. I tell my salesperson; I understand that delivery on a boat over an ocean of salt water requires rust preventative, but must they use burnt motor oil to coat it, and then drive it across the Gobi Desert before placing it into the container. My guess is the sand improves the grip. 

I use many different materials in the products I produce, from sheet to solid stock, ferrous, non-ferrous and quality is an issue in almost every category. 

Nostalgia just isn't what it used to be.


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## Downunder Bob (Mar 11, 2017)

Rustrp said:


> Ah yes, mill tolerances on tubing. I have older stock/data books from my suppliers that detail the amount of twist from end to end or how close the seam can be located to the corner. I tell my salesperson; I understand that delivery on a boat over an ocean of salt water requires rust preventative, but must they use burnt motor oil to coat it, and then drive it across the Gobi Desert before placing it into the container. My guess is the sand improves the grip.
> 
> I use many different materials in the products I produce, from sheet to solid stock, ferrous, non-ferrous and quality is an issue in almost every category.
> 
> Nostalgia just isn't what it used to be.


No it aint.. I don't care much anymore, another 10 or 15 years and it will never bother me again.


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## Rustrp (Mar 11, 2017)

bobshobby said:


> No it aint.. I don't care much anymore, another 10 or 15 years and it will never bother me again.


It will always matter to us when we care about trade or craft. I push back against the lack of ethics concerning product produced and the lack of quality, but I try to not push so hard I'm giving up my power to them. I'm up front in what I expect to be delivered to me and reject poor quality. Keep the faith!


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## LarryJ (Apr 15, 2017)

Cobra said:


> I have often received the same form of flat bar in Canada when buying those small sizes.  It is usually fine for projects that I am welding up frames etc.  I am with Paco, if you need mostly flat, use cold rolled, if you need flat flat use precision ground stock.



+1


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