The steel industry is moving towards the implementation of Industry 4.0, in order to remain competitive in this globalized world, where cost reduction and greater interaction in the supply chain must be thought as a whole. This type of industry is usually done with different and complex processes, a part that manufactures steel and the other where the product is rolled. Due to this complexity and size there is a tendency to implement I4.0 in islands. To assess whether a particular company has the ability to implement enabling technologies for I4.0 or at what level of implementation it is, aptitude assessment and maturity assessment models are applied. Another return that can be obtained from some maturity assessment models is to be a guiding tool for the strategic planning of the implementation of I4.0. Having this in consideration, the present work aims to present maturity assessment models for the implementation of industry 4.0 and to evaluate and start a debate about its applicability in the steel industry. With this aim, eight models applied in several industries were studied and verified if, and/or how, they could be applied in the steel industry, due to its particular characteristics