Resumen
The invention discloses a locking ball head (1) comprising a threaded longitudinal hole (2) configured to receive an end of a threaded rod (200), wherein the mouth portion (2b) of the threaded longitudinal hole (2) comprises a blocking means configured to decrease the diameter of said threaded longitudinal hole (2) for the purpose of immobilizing a threaded rod (200) inserted in the hole (2). This configuration allows to adjust with great precision the length of the rod inserted in the hole (2), and therefore also the length of the complete piece. (Machine-translation by Google Translate, not legally binding)