I've milled a 0.02" slot in a brass bar for a piece of sheet steel 0.02" thick. Trouble is, it's not all that snug (I blame the saw used to cut the brass--or my techique.)
Now how to recover, short of soldering the steel in. The steel and brass have to remain straight, so I can't just go pounding on it.
And would pounding on it even help?
er