Lock Failure???

[Joe Talmadge]

If you whack the spine on something hard enough I would think that the end of the lock leaf would be permanently deformed (shortened). This should result in over-travel of the lock behind the blade. Not good IMO.

While what you say makes sense, I also agree with biogon: "hard enough" seems to be pretty dang hard. While I personally favor lighter whippy snaps for spine whacks, certainly I have liner locks that seem to hold up to anything.

Here's a well-known and very interesting phenomenon: there are some liner locks that will fail the spine whack test exactly once. That is, you do a spine whack, it fails, and then it never fails the spine whack test again!. Someone -- I think it was AT BArr -- explained this as "setting the lock". Someone else -- I think it was Sal Glesser -- disagreed, saying that once a lock shows that it fails even once, it should be considered suspect. This is almost exactly the opposite of what you're worried about! Someone doing a spine whack with this kind of knife will arguably have a safer lock once he's done.

In any case, I personally don't do very hard spine whacks on hard objects; I've found that if there's a lock geometry problem, a light whippy snap is more likely to bring it out.

Joe