Method for manufacturing powder magnetic core, and powder magnetic core

A powder magnetic core comprising metallic soft magnetic material particles and having a worked surface and an unworked surface,

• the powder magnetic core having a drum shape comprising a coil holding part and flanges at both ends of the coil holding part,
• the metallic soft magnetic material particles being bonded together with an oxide layer interposed therebetween,
• the oxide layer containing an element constituting the metallic soft magnetic material particles,
• the coil holding part having the worked surface having an oxide layer containing an element constituting the soft magnetic material particles,
• wherein the powder magnetic core has a ratio of RMD to RAS (RMD/RAS) of 5 or less,
• wherein RMD is the average of arithmetic average roughness Ra values of a worked surface of the powder magnetic core, and RAS is the average of arithmetic average roughness Ra values of an unworked surface of the powder magnetic core, and
• the average RMD of the arithmetic average roughness Ra values of the worked surface is larger than the average RAS of the arithmetic average roughness Ra values of the unworked surface.