This article analyses the particular energy transition of the Swedish iron and steel sector (1800- 1939), a relevant actor in the European context during the nineteenth and twenteenth century. The Swedish iron and steel sector is an interesting case to analyse in the perspective of energy transition and the composition and change of the capital stock (classified by energy technology). An in-depth study of the change of the capital stock in the sector will enable us to study the dynamics of energy transition; moreover, the Swedish iron and steel sector, with particular emphasis in technology adoption, lock-in carbon infrastructure and energy transitions is a powerful tool to understand current difficulties to change our infrastructure towards cleaner energy sources.