Hidden joining device for parts of furniture and furnishing items

A hidden joining device for parts of furniture and furnishing items, said parts including a first panel (11), and a second panel (12), which must be moved towards each other according to an approach direction (d) in order to bring an edge (B) of the first panel abutted in a tightening position against a surface (S) of the second panel, said hidden joining device comprising:

• a blocking group (GB) coupled to the first panel, said blocking group (GB) comprising an elongated bushing or tubular element (31) having:
• at least two traversal pass-through holes (40, 40′), and
• internally threaded sections in proximity to said traversal pass-through hole (40, 40′);
• and
• a connection group (GC) assembled on at the second panel (11, 12), said connection group (GC) comprising at least two pins (34, 34′) configured to engage with said at least two traversal pass-through holes (40, 40′),
• wherein said blocking group (GB) is inserted inside a seat (S1, S1′) that is contained in a thickness (SP) of the first panel (11, 12), and
• wherein said seat (S1, S1′) extends from one of the edges (B1) of the first panel towards an interior thereof, forming a single visible hole (30) in an assembly of the first and second panels;
• wherein blocking grub screws (39, 39′) engage with said internally threaded sections of said elongated bushing or tubular element (31) and said pins (34), and wherein one of said blocking grub screws is perforated so as to allow passage therethrough of a tool to engage with another of said blocking grub screws.