a universal vertical grinding machine has a horizontal base supporting at least one workpiece carrier device . a vertical column centered on the base provides an axis of rotation for at least one collar rotatably mounted with reference to the column and provided with at least one head comprising a grinder - carrier spindle supporting a grinder adjacent the workpiece carrier device . suitable arrangements are provided for effecting an axial sliding of the collar along the column in a reciprocating manner , and to independently rotate the collar about the column . advantageously , there are two collars mounted for rotation about the column , with the collars being rotated in opposite directions .