The acrylic insert demo cube
Key Detail
Here we have a key-locking insert installed in a clear acrylic cube. The yellow highlighted area is the location of the key after installation. The first few threads on the outside of the insert are destroyed by the key---preventing any rotational movement of the insert.
The Demo Cube Details
1/4-20 Low-profile socket head cap screws installed in a 1.5" cube of cast acrylic.
Easy to Install
Easy to install inserts come with a thread-locking compound. You can see the reddish material worked into the threads in the picture to the left. This will help prevent unwanted movement, but it is not going to work for every application.