What cheaper knives pass spine wacking tests?

[znapschatz]

With a slipjoint the spring mechanism holds it open.
With a locking folder, the lock holds it open.

You would not carry a slippie with a broken spring mechanism because it would be too dangerous. There would be nothing to keep the blade from closing on you. (I know. I've got an old slippie with a broken spring and I don't carry it. I keep it in my dresser drawer for remembrance of the one who gave it to me.)

Just so with a locking blade. With most locking blades there is no spring. If the lock fails, the blade can flop back on your hand. A lock failure could cause the blade to fold back on your hand even with the little side pressures that develop during normal cutting. So you have to be assured that the lock works.

Passing a mild spine whack test assures us that the lock will not fail under normal usage. And that is what we are looking for. Assurance.

Well said.

Folding while being used is exactly what my new Leatherman Charge did on me first time out, although luckily, I wasn't cut. A light tap on my rubber soled shoe caused the blade to fail again.

Because of that, I put all of my other locking blade knives and multitools to the same test, and none other failed a spine whack, nor while in use. That confirms to my satisfaction that a spine whack result can predict the possibility of a lock failure.