Originally Posted by
urleebird
* Tarnish is discoloration that can be easily removed with a cleaning paste like Maas or Flitz
* Surface Rust is oxidation of the steel that can be removed with less aggressive sandpapers and does not encroach very far into the steel.
* Pitting is when oxidation has penetrated into the steel at depths that require more aggressive abrasives. It can be speckled or all in one spot. Sometimes, very large spots.
Pitting requires extensive work with a variety of abrasives to eliminate it entirely.
Pitting will cause no further harm to the blade if the active oxidation has been removed and has been neutralized. The full depth of the pitting does not have to be removed to be effective. So, you can have pitting, as long as it has been stabilized...