Hands up if you think flat bar should be flat

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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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
 
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.
 
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
 
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.
 
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?

aluminum.jpg
Denny
 
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

Ziggyboy Whip-it Red.png Ziggyboy Whip-it Wheelie Bar 5.png
 
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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.

alum.jpg
 
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.

Ziggyboy Whip-it Wheelie Bar 6.png
 
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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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