Rtical Wet Stone Grinder

Grinder with vertical axis comprising a grill 4 appearing in the form of a cylindrical ferrule able to be moved axially with respect to the drive axis of hammers 3, characterised in that the grill 4 is constituted by a ferrule having no perforations at its upper portion and comprising perforations at its lower portion, the adjustment of the size grading being effected by moving the lower.