How to make threads

[Pete O]

It appears that you have been trying to create a thread by screwing a screw into a non-threaded hole, you have already discovered the result as the thread on the screw is not a cutting tool. The thing you are working on is a bit hard to identify in your photos, it might be suitable for a simple self-tapping screw if it is a thin-walled tube and the screw is not holding a load, or, if you want to use a nut instead of threading into the metal itself, the hole must be drilled to the diameter of the full thickness of the screw (or bolt) including the thread. Otherwise you will need a tap in the appropriate size for the screw you intend to use.