A solenoid may include a core having a junction surface; a plunger having a junction surface and located adjacent to the core; a shading ring located proximate to an interface between the core junction surface and the plunger junction surface, the shading ring having an outside diameter slightly smaller than the diameter of the core, and operable to produce a concentration of magnetic attraction within an annular range of the interface between a center of the interface and a location of the shading ring; wherein a contact region between the core junction surface and the plunger junction surface is substantially smaller than the respective junction surfaces and located proximate to the annular range of the concentration of magnetic attraction.