Low profile, shielded magnetic components for circuit board applications include self centering core and coil assemblies with coil receptacle and centering projections formed in core pieces that are assembled around a preformed coil. Welding and plating techniques for forming termination structure for the preformed coil avoid thermal shock issues. External gapping elements and agents to form a gapped core structure are avoided, and gap size in the cores may be tightly controlled over large production lot sizes.