Reactor for electrical devices

A reactor comprising:

• a cylindrical coil, made of a conductive wire spirally wound, which generates magnetic flux in response to supply of a current;
• an insulation coating that covers an entire surface of the coil and includes corner portions covering respective corner portions of the coil;
• a core made of magnetic powder-containing resin, the magnetic powder-containing resin being made of a mixture of insulation resin and magnetic powder, the core being arranged to surround the coil outside the insulation coating;
• wherein
• the corner portions of the coil being formed between two opposing axial end surfaces of the coil and an inner circumference surface of the coil, and between the two opposing axial end surfaces of the coil and an outer circumference surface of the coil, when viewed in a cross section that is perpendicular to the direction the coil is wound;
• each of the corner portions of the insulation coating has a curved surface portion formed with a circularly curved surface having a curvature radius of 0.2 mm or more;
• and
• the core abutting the insulation coating, and having an elastic modulus of 5 to 25 GPa at room temperature.