Grinding wheels
— interchangeable nozzles in the form of circles (discs), usually installed on the sole of the corresponding shape. They are intended for initial grinding and preparation for polishing, eliminating individual irregularities, cleaning welds, leveling ends, etc. They can vary in grain size and intensity of grinding, but processing with such a wheel still turns out to be rougher than the effect of a polishing nozzle.
Note that only traditional grinding wheels with a flat surface are included in this category; petal nozzles are placed in a separate category (see the relevant paragraph).