Lighting receptor for a wind turbine blade

A wind turbine blade (10) comprising a lightning receptor arrangement (11, 12) comprising at least an external metallic receptor element configured and arranged in one side of the wind turbine blade (10) in an operative position for receiving a lightning strike, an internal element joined at least to an internal side of a shell (17) of the wind turbine blade (10), and a down conductor (18) of a grounding arrangement connected to the internal element, wherein:

• the external metallic receptor element is a self-threading screw (21) having a head (23) and a threaded shaft (25);
• the internal element comprises an electrically conductive block (20) configured with at least one initially unthreaded hole (41) opening in a surface of the block for cooperating with said threaded shaft (25), wherein the internal element also comprises an insulating coating (27) for the electrically conductive block (20), and wherein the surface of the block abuts and is in direct contact with the insulating coating (27);
• a material of the self-threading screw (21) has higher hardness and lower ductility than a material of the electrically conductive block (20), and the threaded shaft (25) and the at least one unthreaded hole (41) are dimensioned so that the self-threading screw is capable of achieving a threaded connection with the conductive block by a process of threading the self-threading screw (21) into the at least one unthreaded hole (41) of the conductive block (20) with formation of threads in the at least one unthreaded hole, wherein the self-threading screw is secured in the block in the operative position with a top of the head of the screw aligned with an external side of the shell and with an empty space between a bottom of the head of the screw and the insulating coating (27), and with the threaded connection transmitting to the block all lightning currents received by the self-threading screw (21);
• and
• the internal element is joined to the shell (17) with an adhesive force capable of withstanding a torque applied to the head (23) of the self-threading screw (21) for threading it to the at least one unthreaded hole (41).