A low-loss and lightweight core material, with applications in electrical machinery, is made of highly packed and insulated magnetic microwires (MWs). These MWs are aligned in such a way as to guide the flux in the rotor/stator, with the ultimate goal of increasing efficiency and substantially reducing core losses. Commercial FeNiCo-based MWs with a 127 m diameter and a 33 m insulation coating are utilized. The magnetic measurements of the fabricated sample demonstrate high permeability and low core loss in a wide range of frequencies. To prove the utility of this type of material, we used it in the rotor core of a prototype 25 Watt three-phase synchronous reluctance machine (SyncRM). The core is lighter, and the losses are significantly lower than in conventional core materials under the same torque density.