i watched a video of how wire landing gear is made and the same company makes it for almost all company's(made in china)they use different sizes of hardened steel piano wire and it is all squirted out cut and bent in a form in one step,the wire is unrolled from a large spool.no heat treatment done that i saw they packaged it further down the line.i would assume that you can get gear that is tempered after bending but it would cost a bit more.what we use it for isn't as critical as for commercial or private airplanes.i worked on a naval base where they make their own parts and they had their own foundry,most parts were made for submarines and i can say that the process they use was very critical.if you had to grade most of the metals we use in our models a metallurgist would fail almost 90% of it.i don't claim by no means to be an expert but for what i do my cold bending over the years has been sufficient for me and have had no failures.