Disadvantage of threaded fasteners ????Well, most of the threaded fasteners used in general applications have the following disadvantages: 

1. Continued exposure to vibration tends to loosen the fastener.

2. If the fasteners are not creep resistant, they will fail at elevated temperatures.

3. If the members to be fastened and the fastener, both have appreciable differences in thermal expansion co-efficient, both undergo different expansions and introduces unnecessary internal thermal stresses.

4. The sharp edges formed in the threads of the members acts as stress concentration regions and is undesirable. This is to some extent overcome by introducing a small radius at the crests and troughs of the threads.

5. Making threads on the fastener increases the available contact surface. This introduces the chances of contact corrosion (sometimes, according to prevailing environmental conditions).

6. Tighten it too much without knowing or feeling the limit, the screw / bolt neck (just below the screw head) undergoes torsional failure and the fastener cannot be removed. In such a case, the members have to be disassembled destructively (though there are methods like

drilling an almost equal (slightly less) diameter hole in the fastener) -- this is no easy job.