What's the name of this metallic eye?
A part like that is often used as a retainer pin. It would be fitted through a close fitting hole in two parts to keep then from pulling or rotating apart. The small stamped groove on the end is bent after the retainer pin assertion to keep the pin from pulling or vibrating out of position.

Later removal of the retainer pin can be done by bending the tip back inline or simply cutting it off. Usually a pin of this type is replaced when removal and rebuild is done on an assembly that uses such a retainer pin.