Grinders have discs that rotate horizontally to perform various duties, from removing paint and thin coatings to lightly texturing to allow the surface pores to open. The reason they are so versatile is because of the different grinding attachments. The attachments come in various types and grits to allow for multiple applications. Since grinders use rotation instead of impact to remove material, the amount of material that can be removed is restricted to about â…› of an inch, this also depends on which type of attachment is being used.