Buckling Spring Key Switch
The Buckling Spring Key Switch is famously used in IBM Model M keyboard
You press the key, the spring compresses, then at some point, it can't
take it anymore,
, it buckles, giving up all resistance.
That means you get a clean precise feel when the key is activated.
A drawback is that it is very loud. The sound came from the spring hitting
the key's inner wall. It's crispy and precise.
Buckling Spring Switch Sound
Keyboard with Buckling Spring Switch