Hi I am working on a prototype of a pen and I would need to make threads, can anyone help me to find the material? Thanks, all the best Carlos SanchezAlamo

Threads can be done by lathe and tap & die. It gets pretty involved, especially if you need to match a specific thread pitch and so on. You may want to have this done for you, if not, do a Google search and you'll be presented with an abundance of info.