3M 31489 Cubitron Hookit 737U 320 Grit Hook-and-Loop Clean Sanding Sheets Rolls. 3M 34440 Cubitron Clean Sanding Sheet Roll (40+, 70 mm x 8 m, 1 roll per box). Our 3M Cubitron II File Belts 786F is a 3M best-in-class abrasive belt, designed for use with the 3M File Belt Sander, for tasks like grinding out rivets and removing spot welds.