Bicycle Locks

Recently my Uncle threw away 2 bicycle locks, now at my yard they actually accept these things even with the rubber and plastic bits and pieces attached. So I wasn't against taking them. Anyway I was bored and decided to hit the plastic stuff where you insert the other end of the lock into. The plastic came off instantly and I was left with a strange dull gray metal, it was wrapped around where the key goes into. I decided to keep hitting and this gray metal came off to reveal a bright yellow non ferrous metal that I assume would be brass. Not astoundingly heavy but probably worth the effort of extracting it from the lock. I don't know, I honestly just felt like sharing lol. Hope this helps!

-Thanks

that would be the"tumbler" i believe