@lebeginner said:

Hello,
I would like to draws screws for a mechanical system.
I found the screw_21.rb that allow me to draw the basic shape, but I can't finish the screw with a flat face (as in a normal stainless screw.
I tried to make en intersection with a disk, but it doesn't not work.
can someone help me please ?

Do a Forum Search [look at the top right of the screen] for Screw Tutorial, it returns 23 hits - although the first one is of no use because it's a tutorial for a dome and 'screw up' is used in the sense of 'to mess up', the remainder are probably what you are looking for...
Effectuez une Recherche dans le Forum [regardez en haut à droite de l'écran] pour Screw Tutorial, il retourne 23 coups - bien que le premier n'est d'aucune utilité parce que c'est un tutoriel pour un dôme, et «screw up» est utilisé dans le sens de «mettre en désordre», le reste est probablement ce que vous cherchez ...