Engraving on metal with a simple pencil from 220V

This experiment is only for those who are versed in electricity, do not try to do it yourself.

A pencil lead conducts electricity so that a voltage of 75 watts is placed in the load. Of course, this method works from other power sources, but ours is described when working from 220 volts.

What is it for? For example, for marking metal products, this way you can put an inventory number or decorate to taste.