Counter Bore.
Not not the presidential debates.
This is where you want a bolt to be flush with the surface of a hole.
Or maybe you need to drill a flat bottomed hole for a spring to fit in or any other reason.
I did this yesterday and it worked great.
Sadly I had never thought of it before.
Here I will post a link to the guy I learned it from on YouTube.
No he isn't one of the top guys but his videos are well worth watching.
Yes you will see my comment.
https://youtu.be/qwuSBJFa5uM