Men of steel (1932)

James Harg and his father work in a steelmaking plant which is incompetently run, with scant attention being paid to worker safety. In his own time, Harg works on ideas for a revolutionary new manufacturing process for hard steel. When his father is badly injured in a workplace accident resulting from employer negligence, Harg uses some of the compensation payment to develop his invention to a stage where it can be tested in practice. It is a huge success and Harg patents his process. He rises to a position on the board of the company, before staging a coup to oust his former employer and take over the business himself.