I've never had a lot of faith in ball bearings, and wondered if anyone has used tapered roller bearings?
One problem to overcome with tapered rollers would be getting the "preload" correct
the other issue would be the lack of properly sized (small enough) tapered roller bearings,
lastly their greater axial thickness...
But should these issues be overcome, they'd be far stronger....
OR alternately using a sealed double-roller for the pivot and roller thrust washers on either side,
but I suspect either method would fit deeply into the category of "turd polishing", a grossly excessive solution for a fairly simple need. (Bronze and Teflon washers work)
Mind you for the point of FULL DISCLOSURE I'm sitting here at my desk playing with my first Ball Bearing flipper knives, which one is actually first is debatable, but both arrived with today's mail...
Both Chinese (Taiwan) branded "Doom blades" (so I have less than $30 (a touch more than a Chinese Kershaw) invested between them). My only real complaint is that the factory edge has a "micro-bevel" that was done wit too fine a hone (or diamond) so it's hard to make the edge "catch"...