Die-cast aluminium polishing, also called sandpapering, is a finishing process where an abrasive cloth, known as sandpaper, is manually passed on the corundum of the pieces in order to smooth the surfaces.
This operation can be repeated several times depending on the quality of the starting surface and result desired. There are 4 types of abrasive paper for sanding which correspond to the respective grinding process phases: roughing (60 ÷ 120 grit), semi finishing (180 ÷ 400 grit), finishing (400 ÷ 1000 grit) and superfinishing (grit above 1000).
The die-cast aluminium polishing usually depends on the use of the pieces in coupling with others for mechanical features, but also for subsequent finishing activities, such as painting.