Dross growing on immersed rolls is responsible for defects on the galvanised strip. It is essential to identify the mechanism of this accumulation on immersed hardware. An industrial approach has been followed: stainless steel samples (316L) were set up at several locations on the moving rolls and on the static members through a galvanising campaign. The samples were then analysed by means of optical and electron microscopy. The results from this first approach pointed out significant effects of some factors referred to as “location” and “moving”. Further investigations, including a deeper analysis of several parameters, are requested to validate the proposed mechanisms.