Ka-Bar's got some pretty tough folders. I own a Ka-Bar Mule, and I reviewed it on this forum some time ago. It is one tough folder, and the Dozier family are also pretty tough folders from Ka-Bar. I abused mine pretty rigorously when I got it, and the lock held firm. For the money, it is a good investment.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)