when do you decide...

[Rickthepick]

that a lock is internally damaged?

Iv had a few padlocks that cannot be opened, they are usually well weathered and seem unusually difficult to pick. i think one is just a 4 pin

Im a pretty accomplished picker so i get quite frustrated when i come across something like this.

my only guess is that the springs are corroded as you dont seem to get much feedback from the pins. Its only ever been padlocks so im assuming the outdoor use is the key

Cheaper tri-circle locks seem to suffer from this when used outdoors.

[Rickthepick]

Nobody else going to admit to being beaten

[FarmerFreak]

It isn't that we aren't going to admit defeat. This sort of thing happens.

It's just that the answer to your question has many variables. This isn't a question where one answer fits all problems. Yes, corrosion is a bad thing.

If you/I ever get a lock where the plug doesn't wiggle at all, even with heavy tension from a screw driver. I can tell you that that lock isn't worth the time to even try.

If it is a stuck driver pin and a smashed spring, it may be worth the time to work on it. Pending on other variables, how corroded is the rest of the lock? Can the lock be taken apart to be fixed? etc...?

Are all the pins moving, but it may be something behind the cylinder preventing it from turning? If that is the case, how can you be sure that you have picked it before trying to force it with a screw driver? It may feel picked, but if a lock feels old and crunchy, it will be hard to tell the difference between a set pin and one that has been falsely set. And again is it even worth the time? Can the lock be taken apart and repaired? Will lubricant fix the problem?

Just FYI, the padlocks that I run into in the business that I give up on faster than any others, are locks on spare tires, and hitch locks. I live in Salt Lake City, and the condition these locks are in are very very bad. Unless during the winter seasons (when the streets are coated in salt to prevent ice) the owner of the lock takes extra care and lubricates the lock(s) often. These locks get corroded beyond repair really fast.

[TheSkyer]

Have you tried a little ABUS spray to lubricate your locks? I've managed to get open some pretty badly corroded locks just by lubing them thoroughly