Experimental Study of the Self-Locking Properties of Components of the ITER Blanket Attachment

The article presents a description of the threaded elements of the ITER blanket and analyzes the nature of the forces acting on the threaded elements under ITER conditions. The Junker test method for verifying self-locking properties is reviewed, and test results are presented for an M24 threaded pair that is part of an electrical connector assembly. The article notes that metric threads exhibit unsatisfactory self-locking properties, as does the EMUGE Self-lock thread, when combined with a low-friction coating at mean stresses in the bolt shank below 35% of the yield strength. However, at mean stresses in the bolt shank reaching 40–50% of the yield strength, no loosening of the threaded pair occurs.