I noticed that all of the fasteners on both the Shiz & Otan are hex, but the pocket clips are torx.
I'm going to end up disassembling, cleaning (degreasing), and applying blue Loctite to the main pivot pin on my Otan - it's loosening during repeated use.
I keep the pins in all my folders tight enough so that there's enough resistance to require a deliberate effort to open them & ensure there's no play between the handle and blade when open.
Being OCD about gear PM, I detail strip my blades the moment I can't clean out the detritus with Q-Tips / compressed air. - It's a thing...