I would like to build picture frames, where there on the back is a hole with 18mm in diameter and 7mm in depth. In the hole will I glue a 2mm metal plate.
On the wall would I like to screw in a magnet, like the one below, which is 16mm in diameter and 5mm in depth.
The picture frame will rest on the top of the magnet, and the magnetism will prevent the frame from tipping.
Is it possible to screw an M4 machine screw like the one below into a brick wall?
If so, what is required?