Tube bender die clearance - is square tube .015" underside going to make a bad bend?

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Hi all,My shop is a school in a remote part of West Africa. I'd like to add a tubing bender to our arsenal, thinking a JD2 32. We'd mainly use it for square tube. Our steel over there is metric, so I'd be ordering a 25mm square tube die. However, none of our steel vendors stock that tube over .080" wall thickness. I'd like to preserve the option of bringing some heavier wall 1" square tubing over from the U.S. at some point via ocean freight (we send a container every few years).So, I'm thinking of ordering the 1" square die hoping that it will work for both 25mm and 1" square tube. The difference between those is .4mm which is only .015".I assume a die that's far too big will let the tube widen up and down and flatten side to side too much in the bend. This amount is so small though, that I can't really envision a problem, other than maybe the tube widens .015" more with a 1" die than it would with a 25mm die. If it mattered, I suppose I could even cut a pair of .007" shims to put on the top and bottom sides of the tube when we put it in the die before bending.The amount is so small, I just can't imagine it mattering - but I'm new to tube bending.So, am I asking for trouble trying to make a 1" die do both, or is this really as small a deal as it seems to me?Thanks!
Reply:The thread title meant to say *undersize*
Reply:I think it will depend on the wall thickness. Thick tube will bend with less distortion.There is an easy fix for this problem. Get the 1" die, then make a shim that will bring the opening down to the correct size. I suppose a shim of 0.4mm would be perfect. Tack weld the shim in place, for use on 25mm, remove it for 1".Ian TannerKawasaki KX450 and many other fine tools
Reply:With the collapser piece on the inside of the radius, the tube will tend to swell a little anyway. If it is too much make a shim like above.