Absolute noob question: How do I install a push button professionally on a (self made) console? Many buttons come with a thread. Some of them also feature a screw nut and some kind of snap ring.
The snap ring as you call it is a spring washer. This is placed between the panel and the nut to give extra retention. Using a spanner (or wrench if you are of the U.S. persuasion) to tighten the nut is more professional than using the electronic engineered pliers.
Normally they come with a nut but those with just a thread you have to supply your own nut. Some switches have a washer with a small lug bent at 90 degrees. This is placed in a blind hole to stop the switch rotating. This is used on mainly toggle switches.
So basically a button just stays in position because the hole in the (hopefully robust) panel is smaller than the screw nut and some other part of the button.