i learned that the hard way. after i busted the tip, i thought the whole thing was broken. then i found you can buy replacement tips, so i bought 4 of 'em. when they arrived, it was 4 packs of 2 (!), but i have no doubt i will manage to go through them.

it's also worth mentioning that at the LBS which deals with a lot of older donated bikes, they always just cut the chains off, rather than wasting their own time and wearing down the chain tools. i had never tried that before, but i think i'll do that from now on. even though my bolt cutters aren't nearly as beefy as their are.