Hands up if you think flat bar should be flat

[Rustrp]

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.

View attachment 227875

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.

 

[chips&more]

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

 

[Rustrp]

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'.

 

[Downunder Bob]

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.

 

[Rustrp]

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.

 

[Downunder Bob]

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.

 

[Rustrp]

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!

 

[LarryJ]

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