The screw font
Via Mastodon I was made aware of the font "Schraubenkiste" (screw box). It is a font which includes various screw heads and even allows specifying their diameter and pitch. You can find it here: http://www.peter-wiegel.de/Schraubenkiste.html
Peter Wiegel designed it in his free time and allows it to be used commercially too. If you have any other question regarding the use of his fonts, there is an FAQ on his homepage https://www.peter-wiegel.de/index.html, for english you just need to scroll down a little bit.