A bobbin for an electromagnetic inductive wire coil, to which at least one terminal is attached, has a hollow body with two opposite ends. A side flange is molded integrally to each one of the opposite ends. Each side flange has a plurality of corners and at least one reverse L-shaped rib configuration in at least one corner so that the rib configuration prevents rotation of the bobbin and breaking off of the terminal when a rotational force is applied to the terminal. Another reverse L-shaped rib configuration may be positioned upside down in another corner of each side flange. The reverse L-shaped rib configuration may have a third rib molded integrally thereto to form a reverse C-shaped rib arrangement to confine a rear end of the terminal. This confinement helps to prevent backward movement caused by a head-on force applied to a front end of the terminal.