Added a 20 mil tolerance so that the bolt should press into there firm enough that it will stay but not be too hard to push in by hand. if your bolt is slightly larger heat it up and melt it in.
I added the file -fillet which has a slight fillet on the washer face so it doesnt scratch up a painted surface too much.
M8-1-25_knob.STL | 60.7KB | |
M8-1-25_knob.thing | 14.8KB | |
M8-1-25_knob_fillet.STL | 120.2KB |