Guess this should go in that "miscellaneous" section that doesn't exist yet, but..I do. I'm looking for input on an appropriate strength to heat treat a 4130 landing gear. Actually it's the tailwheel strut of my Kolb, which has bent a couple if times. I pulled it, heated it up, and bent it back straight again, but likely it'll just bend again (it's 5/8 diameter tubing). It is intended to flex for some spring action. Obviously I don't want to harden it to the point it gets brittle, but something higher than annealed or normalized might make it hold up better. But I have no idea what's a typical value for spring steel gear legs. -Dana Starve a feeding bureaucrat...vote Libertarian.