A 64th? (He asks after doing some math?)
That’s heavy enough I’d want to use an edge tool of some sort if it were wood. Take forever sanding, unless you’re using a belt-sander or 60 grit at the lathe, in which case you’ve overshot before you’ve begun. 🤪
But seriously, I often work to 1/128 inch when doing things bigger than pens, and on pens, I try to get the wood matching the metal parts well enough that I can’t feel a catch with a fingernail. Mind you, I don’t actually measure any of those fine measurements, except by comparing two pieces… “oh, this one is just a hair bigger!”