A stator is described herein comprising a first longitudinally extending slot having a cavity defined by a first inwardly facing longitudinal surface and a second inwardly facing longitudinal surface; said stator further comprising a spacer provided in said cavity of said first slot, said spacer comprising a first spacer component that comprises a first sheet of material having a first sheet surface facing inwardly into said slot and an opposite sheet surface that is in contact with and extends along the first longitudinally extending inner surface of said slot and wherein said inwardly facing first sheet surface of said first spacer component comprises at least one ridge projection extending along its length L. Methods for assembling such stators are also described.