Only 35 high end Schuler servo stamping presses exist in auto manufacturing worldwide and the one at Tesla is the first one in the US. The equipment has allowed Tesla to form unique parts, like the Model 3 front fender, which engineers say has greater depth in a single piece of stamped steel than any other fender in production. Tesla chose to build a factory to handle all of its seat production, making it unique in an industry where its competitors all outsource seats.
This is a good article highlighting manufacturing of the Model 3.
Read the article at Bloomberg.
If you want to learn more about materials selection on the Model 3, head over to Teslarati.