Element of fastening accessories to metal windows and doors

Element for fastening accessories to metal window and door frames, comprising:

• a monolithic metal body with a cylindrical central portion having a threaded inner hole,
• an insertion portion with cone frustum shape with decreasing diameter from the diameter of the cylindrical central portion towards one end,
• a stop portion comprising a circumferential throat delimited by a shoulder whose outer diameter is greater than the diameter of the cylindrical central portion, the outer diameter of the shoulder being joined to the cylindrical central section by means of a cone frustum shaped segment,
• a first series of through longitudinal grooves that extend on a part of the length of the cylindrical central portion and on the insertion portion and which define a first section able to be deformed elastically inwards relative to a non-deformed resting configuration, and
• a second series of through longitudinal grooves that extend on a part of the length of the cylindrical central portion and on the stop portion and which form a second section able to be deformed elastically inwards relative to the non-deformed resting configuration.