Standard external thread in a standard internal thread:

In standard screw connections, there is a high concentration of stress on the first thread while load on the other threads is drastically reduced.

This is a natural result of the pitch differences between external and internal threads.

The concentration of tightening force on the first few threads of a standard thread often leads to stripping of the nut thread, especially in soft workpiece materials.

Standard external thread in an EMUGE SELF-LOCK internal thread:

A standard external thread in an EMUGE SELF-LOCK internal thread yields a self-locking screw connection that can be used repeatedly.

The special profile of the SELF-LOCK thread allows an even distribution of stress over the whole thread length.

Link To EMUGE "SELF-LOCK" technical information/catalogue.