How does item durability works?
Title. During my homebrew campaign I planned to throw some Rust Monster at my players since they are going to visit a warped mine that is partially covered of meat, skin and other aberration kind of things. The mob fits perfectly in that kind of environment and also add a real value to my story, so I started studying its stats and abilities and discovered its "Rust" ability which deals damage to metallic items.
I searched for more information on item durability and found the nethys' page related to item damage (https://2e.aonprd.com/Rules.aspx?ID=2160).
Sadly I find it not that helpful, the system is the same as shields but does not go into details. Shields all has a durability, hardness and a broken threshold clearly written, but that isn't the case for non-defensive items such as swords.
Picture this: The Rust Monster attacks one of my player and manages to hit his sword, the sword takes 2d6 dmg. At which point do I consider the sword to be broken? What about metallic armors? Does a steel longsword has the same hitpoint as a steel shield? If yes, what about its hardness then, is it the same? And what about metallic armors, is it more durable than shield?
I guess you get the point.
If you have any thoughts on this subject or happened to have a similar experienced, please help.