Bush for the assembly of panels or furniture pieces, which comprises: - a support body susceptible of being housed in a hole formed in a wall of a panel or of a furniture piece, said support body being provided with a perimetral wall, which o delimits an inner seat, o is provided with an upper edge defining an access opening to said inner seat, and o is provided with a transverse through hole for connection to said inner seat; said inner seat being capable of housing the head of a screw having the shank placed through said transverse through hole, said bush being characterized in that it comprises: - a covering lid, removably associated with said support body closing said access opening, and comprising: o a support layer provided with an inner face facing said inner seat, ∘ a coating layer fixed to said support layer, provided with an outer face facing in a direction opposite that of said inner face and provided with a surface finish developing along a first preferential orientation direction; - fastening means for removably connecting said covering lid to said support body and comprising: ∘ at least three holes formed on the upper edge of said perimetral wall and arranged at the vertices of a regular polygon, ∘ at least two protruding elements projecting from the inner face of the support layer of said covering lid, said protruding elements are susceptible of being inserted into pairs of said holes to connect said covering lid to said support body in at least three distinct angled retaining positions, angularly oriented with respect to each other. - a support body susceptible of being housed in a hole formed in a wall of a panel or of a furniture piece, said support body being provided with a perimetral wall, which o delimits an inner seat, o is provided with an upper edge defining an access opening to said inner seat, and o is provided with a transverse through hole for connection to said inner seat; said inner seat being capable of housing the head of a screw having the shank placed through said transverse through hole, o delimits an inner seat, o is provided with an upper edge defining an access opening to said inner seat, and o is provided with a transverse through hole for connection to said inner seat; said inner seat being capable of housing the head of a screw having the shank placed through said transverse through hole, - a covering lid, removably associated with said support body closing said access opening, and comprising: o a support layer provided with an inner face facing said inner seat, ∘ a coating layer fixed to said support layer, provided with an outer face facing in a direction opposite that of said inner face and provided with a surface finish developing along a first preferential orientation direction; o a support layer provided with an inner face facing said inner seat, ∘ a coating layer fixed to said support layer, provided with an outer face facing in a direction opposite that of said inner face and provided with a surface finish developing along a first preferential orientation direction; - fastening means for removably connecting said covering lid to said support body and comprising: ∘ at least three holes formed on the upper edge of said perimetral wall and arranged at the vertices of a regular polygon, ∘ at least two protruding elements projecting from the inner face of the support layer of said covering lid, said protruding elements are susceptible of being inserted into pairs of said holes to connect said covering lid to said support body in at least three distinct angled retaining positions, angularly oriented with respect to each other. ∘ at least three holes formed on the upper edge of said perimetral wall and arranged at the vertices of a regular polygon, ∘ at least two protruding elements projecting from the inner face of the support layer of said covering lid, said protruding elements are susceptible of being inserted into pairs of said holes to connect said covering lid to said support body in at least three distinct angled retaining positions, angularly oriented with respect to each other.