Straightening a bent lever , Annealing 退火

 Bent Lever. You should be hammer it straight as the alloy is hardened and will fracture if brutally straightened.

 Tools needed : Butane Torch (cheap) . Steel pipe (anything larger then the ball). Any clamp.

 Aluminum has melting point >650 Cel; It soften at around 650F (~340 C). One method I saw in Youtube is using soap , wood as an indicator of annealing temperature (We got no thermocouple!) I found lead has a melting point near 340C. So it is easy. Just clamp a piece of lead and touch the lever to see if it reaches the annealing temperature. It works well.

 Bent softly with the steel pipe. Just gently.

Touch the heated lever with a piece of lead. It melts when the aluminium lever reaches the annealing tempearture.  This is how the lead piece looks like.

Now it is straightened without using brutal force/ hammer. It is rapidly put into cold water to restore the hardness.