Not sure if this will help anyone, but I learnt a little while back there is a bolt mesh add on you can use and looks really good too. Just type bolt and it'll show up in the add on menu. You can create all types of nuts and bolts with ease.
I think it's also worth it to buy one of those collections in the Blender Market that has tons and tons of little models of bolts and other minute things that help with the micro details. It's a pain to model every little thing, we might as well focus the energy into other important things.
