Grey cast iron (GCI) and compacted graphite iron (CGI) are the most employed materials to manufacture cylinder liners. The use of diamond tools to hone the surfaces resulted in an increase of the so-called folded metal occurrence. This irregularity can reduce the performance of engines and investigations to understand it have been made. In this sense, the current study aims to correlate the variation of graphite and the folded metal occurrence. Different samples of GCI and CGI were extracted directly of engine blocks, resulting in four metallurgical conditions. Topographical analysis was conducted in an optical interferometer and a dedicated routine to count the folded metal was developed using 3D images. Folded metal occurrence can be associated to a specific region of topography and to an increase in the graphite area fraction. Experimental evidences were provided revealing cross-sectional images of grooves using a scanning electron microscope. In addition, the present investigation shows that a larger amount of folded metal was related to the microstructure of thicker walls of compact graphite iron. PAPER Nomenclature CGI Compacted graphite iron C-thin Compacted graphite iron from thin wall C-thick Compacted graphite iron from thick wall GCI Grey cast iron Grooves width Average of grooves width (µm) G-thin Grey cast iron from thin wall G-thick Grey cast iron from thick wall Graphite area Area of a specific graphite (µm 2 ) Graphite area fraction RECEIVED