PURPOSE: To prevent slip-off of a belleville spring, etc., and prevent forgetting of application by fitting the belleville spring or a washer on the nonscrewed part of the head part side of the screw, and arranging the engaging projections for preventing the slip-off of the belleville spring, etc., in the peripheral direction of the peripheral surface of the nonscrewed part.

CONSTITUTION: A belleville spring 2 is fitted on a nonscrewed part 3 as stage part of a screw 1, and engaging projections 4 consisting of projecting stripes in the longitudinal direction are formed in the proper intervals along the peripheral direction on the periphery of the nonscrewed part 3 under the belleville spring 2. The degree of projection is made lager than the inside diameter of the belleville spring 2. Further, the engaging projection 4 is formed by fitting the belleville spring 2 on the nonscrewed part 3 of the already prepared screw 1 having stage attaching a knurling tool 5 on the peripheral surface of the nonscrewed part 3, and carrying out knurling work. Accordingly, the engagement of the belleville spring 2, etc., in the nonscrewed part 3 is enabled, and the manufacture with the simple structure is permitted at a low cost.