i've made heaps of bars and the best way to do it is:
1 steal a THICK trolley bar

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2 get a old set of steel 1 pc bars (or buy the same diameter steel tubing)]\
3 then get the barstem and grind diagonally from the top so its 'v' shaped
4 then get a 1/2 round file and file like a madman until that 'v' shape looks like a 'u'
5 then get the TOP BAR and put it in a vice, then heat in the areas you want to bend up and bend to shape
6 let it cool at room tempeerature and make sure its touch cold before doing the 2nd bends.
7. whilst the bar is red hot get some tongs and rest it on a flat surface to make sure that the bends are even (also if you want backsweep, nows the time to do it)
8 insert top bar into bar stem and crimp to fit.
9 get welding flux and rub it in desired crevaces
10 get short pieces of wire and rest in crevace and heat the whole surface evenly and take your time. the better you do this the better and stronger the bars will be
11 make sure to repeat step 10 over the whole area and in all the corners
12 give the bars 1 final heat over so the wels pools and sinks in well
13. if you want the bars to look REALLY good then grind the welds flush
14. sand the living shit out of it, from really coarse to really fine and it will end up a beautiful shiny chrome colour, but you will need to clearcoat it, esterpol works best, otherwise just roughly sand it and spraypaint. DO NOT LEAVE THE METAL EXPOSED, it will rust
if you do that you will have AMAZINGLY good bars!