PURPOSE: A nut for locking a tuning bolt in an RF-filter is provided to implement accurate tuning by supporting the tuning bolt while maintaining the adhesiveness state of a cover plate. CONSTITUTION: In a nut for locking a tuning bolt in an RF-filter, a housing forms a plurality of opened cavities. A cover plate(19) forms a female screw hole. A nut(33) is adhered to the top side of the cover plate while being combined with the tuning volt and the screw. An unfastening prevention protrusion(33c) prevents the slip of a nut. A slit(33a) opens the female screw hole(19a) of the nut and has a certain angle from the top side of the nut. A protrusion has a saw tooth shape.
