The paper provides the first systematic overview of cast steel bell production by the Carniolan Industrial Company in Slovenian scientific and technical literature. It starts by describing the wartime context of copper bell requisitions, which led to the first designs and technological advancements in the production of cast steel bells at the Jesenice Ironworks of the Carniolan Industrial Company during 1916–1929. Baffled by the poor sound quality of steel bell prototypes, the shrewd master founder Franc Torkar and the head of the foundry, engineer Karl Bachmann, saw no other alternative in the summer of 1918 but to adopt the well-established design for steel bells that had been manufactured for some time by the steel foundry of Bochum. Based on said model, they continued to improve the Carniolan Industrial Company’s steel bellfounding designs until the end of 1922, producing about 2200 cast steel bells.