Patent ID: 8313834

Claim:
A core for a reactor obtained by press molding metallic magnetic particles, wherein: the metallic magnetic particles are coated with an insulating coated film, the metallic magnetic particles have: a mean particle size of 50 μm or more and 70 μm or less; a variation coefficient Cv which is a ratio (σ/μ) of a standard deviation (σ) of a particle size and a mean particle size (μ) of 0.40 or less; and a degree of circularity of 0.8 or more and 1.0 or less, the metallic magnetic particles have an outer coated film surrounding the outside of the insulating coated film, the outer coated film has at least one of a heat-resistance imparting protective film and a flexible protective film, the metallic magnetic particles substantially contain iron and inevitable impurities, an amount of the inevitable impurities being 0.1 wt % or less, the degree of circularity is an average of values determined according to the following equation by observing the cross section of randomly selected 1000 or more metallic magnetic particles under a microscope, and calculating the area and the peripheral length of each metallic magnetic particle, and the degree of circularity=4π×Area of metallic magnetic particles/(Peripheral length of metallic magnetic particles) 2 .