means of electrochemical machining process ecm the groove shapes and widths as well as the groove density along with a decrease in the flight height provide the overall bearing performance the grooves in some embodiments may serve as microchannels for fluid delivery and distribution among the embodiments of this invention electrochemical machining is a manufacturing technique that could be used to fabricate grooves on fluid dynamic bearing workpiece parts of various geometries as explained above the ecm apparatus consists of the electrode the electrolytic bath the workpiece part and the fixture that sets a specific gap between the electrode and the workpiece applying the electric potential at high electric currents through the gap allows for pattern transfer from the electrode to the surface of the workpiece part the depth of the resulting groves depends mainly on the machining gap the electric current and the deposition time the widths of the grooves as well as their shape and their density the number of grooves per unit area of the part are defined by the machining gap between the ecm electrode ecm apparatus and the workpiece the electrolyte flow rate through the machining gap and the feature geometries of the ecm electrode these factors could determine the width and wall straightness squareness of the grooves geometries on the part the widths of electrochemically machined grooves on the workpiece parts are generally larger than the original features on the electrode due to the phenomenon called the overburn one of the main.