I have always bent mine cold,while I am fully aware that steel when bent this way can and does crystallize, for all practical purposes I have never had a problem with my landing gears, then last week I went to bend a 5/32 one cold in the vise and it exploded in three pieces and it did not take much pressure, my guess is it was hardened too much, I then took a scrap piece heated it with a propane torch and it was so much easier to bend and get an precise angle, it did not seem to take the temper out too bad probably because I only heated it till it started to bend to avoid annealing it.