The flint key holds up pretty well for several strikes. I have never put it through a stress test to see how many that it would endure. It would basically be a few-use type of tool to be replaced if ever really used. I came up with the shrink tubing after having an "unprotected" flint key on the keychain, and, after it tossed and turned in my pocket and got banged against everything else, a couple of the individual flints popped off.