One of the more common cause of the superficial failure and the subsequent downgrading of hot rolled steel coils is the scale formed during the different technological phases which cannot be removed at adequate efficiency. The industrial test series launched by DUNAFERR Steelworks Co. Ltd. had the aim of following up the scale formation of six different steel grades-starting from the reheating furnace till the coiling of hot rolled strip-with the aim to assess the efficiency, possibilities and deficiency of the actually operating descaling system for the grades representing the major part of the production. The paper focuses primarily on the structure, phase composition and properties of scale formed in different stages of production and presents the measurement results in the mirror of accurately measured and recorded industrial parameters. Based on the results can be stated that due to the increased scaling susceptibility and the unfavourable characteristics of the formed scale the greatest challenge for industrial specialist is represented by the steel produced for electrotechnical use containing 1.5-2.1 wt% silicon. For this grades it is recommended to elaborate a more effective mechanical descaling and adequate pickling technology.