A solenoid includes a stator core, a plunger, a ring core, and a magnetic circuit component. The stator core has a fixed axial end and a free axial end. The free axial end is unfixed. The stator core is formed of a magnetic material. The plunger is slidable along an inner surface of the stator core. The plunger is formed of a magnetic material. The ring core surrounds an outer surface of the free axial end of the stator core. The ring core is formed of a magnetic material. The magnetic circuit component is adjacent to the stator core. The magnetic circuit component conducts magnetic flux with the stator core. The ring core radially conducts radial magnetic flux with the stator core. The ring core axially conducts axial magnetic flux with the magnetic circuit component.