Wound core

A wound core comprising:

• a substantially rectangular wound core main body in a side view,
• wherein the wound core main body includes a portion in which grain-oriented electrical steel sheets in which planar portions and corner portions are alternately continuous in a longitudinal direction and an angle formed by two planar portions adjacent to each other with each of the corner portions therebetween is 90° are stacked in a sheet thickness direction and has a substantially rectangular laminated structure in a side view,
• wherein each of the corner portions has two or more bent portions having a curved shape in a side view of the grain-oriented electrical steel sheets, and the sum of bent angles of the bent portions present in one corner portion is 90°,
• wherein each bent portion in a side view has an inner side radius of curvature r of 1 mm to 5 mm,
• wherein the grain-oriented electrical steel sheets have
• a chemical composition containing, in mass %, Si:
• 2.0% to 7.0%, with the remainder comprising Fe and impurities, and
• a texture oriented in the Goss orientation, and
• wherein when interlaminar friction coefficients, which are dynamic friction coefficients between a plurality of two laminated grain-oriented electrical steel sheets facing each other, are measured at least at one of the planar portions of the wound core main body for a plurality of the two laminated grain-oriented electrical steel sheets having different positions in a thickness direction of the laminated structure, more than half of the measured interlaminar friction coefficients are 0.20 to 0.70, and an average value of all of the measured interlaminar friction coefficients is 0.20 to 0.70.