A solenoid assembly of a fuel pump is disclosed, including a housing having an open end and a partly closed end; a pole piece fixedly disposed within the housing; a bobbin assembly disposed within the housing and including a coil disposed proximal to the pole piece; and a bobbin retainer disposed between the open end of the housing and the bobbin assembly, a radially outer surface of the bobbin retainer contacting the housing. A portion of the housing which is adjacent the bobbin retainer has an outer surface that is recessed and an inner surface that protrudes against the bobbin retainer. The portion is created by deforming the housing to create the protrusion on the inner surface of the housing. The housing inner surface protrusion provides a press fit engagement with the bobbin retainer.