It's not just the fabrication but also the heat treatment (and the energy bill). Small parts can be heated with an acetelyne torch and then quenched in oil. A bolt will require an oven. You'd have to have a rich customers to help pay for it or send it out to a place that does.
Take some machine shop classes and GTAW (TIG) welding before you go to school.
Vigilantibus et non dormientibus jura subveniunt. Molon Labe!