Help with measurements when bending 1/2 steel
 

Help

I need to make a few bends in some 1/2 x 2 flatbar for the steering box mount I'm fabricating.

I'm basically making a "Z" shaped bend. I've taken a chunk of coathanger and bent up a template but I'm having a hard time deciding how to measure between the bends due to the thickness of the 1/2 flatbar. Any idea what the bend allowance is?

Do any of you metal gurus have any helpful tips or rules of thumb? I'll be using the time honored farm boy method of clamping the metal in a vise and heating it with a torch.

Thanks
Bobby

I bend sheet stock all the time for aircraft repairs and such but when I work with stock as thick as 1/2 like you want to do I either "V" cut the stock 3/4 of the way through at my bend locations then weld after forming, to get a tight bend radius or I cut separate pieces, V grind them, then weld the assembly together.

Gary

Google "bend allowance calculator", there is a simple spreadsheet at toolingbydesign.com that works great

Good advice here....

Thanks guys
I'm probably over thinking it. Thats what happens when its cold in the garage and I'm feeling lazy.
In the long run, I'd really like to bend up some steel and have it fit the first time....LOL

Good information, thanks
Bobby

I looked at that design and ended up going with the mount AX designed. It uses a piece of angle iron (I think I went with 2 1/2" x 1/4" thick). It was simple to make and only took an hour or so).

http://i935.photobucket.com/albums/a...ps6cac7767.jpg

Bobby..

easiest way... cut it long.. make your bends in the middle... put it in place..cut off the extra.. works everytime.. it helps to have a 4.5" to 6" grinder with a .040 cutoff wheel...of if you have all day a band saw.

j:-X06

Because I am mathematically challenged :-X19, I heated and bent the first bend, then used the coat hanger template and bent the other end to match...came back and cut the ends off as jnolin suggests, worked great for me. I felt like a rocket scientist when I finished! :-X04
w

I'm not a high tech guy, I do a bit of metal work and have done cold and hot bends. 1/2 thick material will be a chore to bend cold.
The radius you are making, and if done hot or cold will determine the amount of material it takes to roll over the radius. Even so I'm thinking that if you need an exact piece when you heat it in a vice and beat on it with a hammer you will not be able to yield precise results. You can use a test piece, make your bend and measure your outcome to determine how much to give your bends or as suggested you can bend, cut, and weld or simply weld up your piece.......because of the thickness, I would opt for the latter as it is the least amount of work and will look really nice when sanded. The welds when done with MIG should be stronger than the cold steel you are using, and if needed you can sand a radius on the outside corners if needed.
My next question would be: Can a lighter steel be used to gain the strength you are seeking? 1/2" seems pretty hefty.
regards,
T.

Thanks guys
I really appreciate all of the suggestions and tips.

From further looking at it I won't be making a "Z" shaped bracket afterall. So, I'll just need to make an approx 30 degree bend in the flatbar.
I'll make the lower section as a seperate piece and then weld them together.

So the good news is that I can use John's method of making the bend and then cutting the ends to fit.

I chose 1/2" for a couple of reasons; First, I had some material laying around, and Second, gut feeling is that the bracket should be stout...LOL (I also have some 3/8 x 2 flatbar, maybe I'll use that)

Bobby