if the bend is returning, your not getting it hot enough. if your careful, you dont have to burn the shaft to get enough heat either. if you watch when your heating a spot, it will appear to turn waxy. then its ready to bend. it will bend easily, so be careful you dont bend it too far. i use a 2 temp heat gun, and use it on the low setting. ive never tempered the shafts ive made. the tonkin stakes your using is usually strong enough to stay straight for a long time. ive done plenty of unintentional tests to prove it! lol