A base for sanding machines, grinding machines or the like includes a body (10) connectable to a machine (M) or integral therewith, the body (10) being provided with at least three supports (P) arranged in such a manner that their ends (P′) lie on a plane (L) and configured in such a manner that at least one tool (T) of the machine projects at least partly beyond the plane (L) by a portion (D), the body (10) being provided with elements adapted to vary the position of the plane (L) with respect to the tool (T).
