I buy my nutserts from Rivnut Australia so what am I using???
I've used some that are 10mm OD but these ones are 9mm OD which I learnt the hard way with laser cut holes.. Mostly I use them with powdercoated parts and there is a bit of an art to choosing a hole size that allows for the powdercoat without needing a hammer.
I'd happily use them for linear rails but I'd like a recess that allowed the rail to sit flat on the frame, not on the nutsert.
How have you found the rails sit on the nutserts v's an accurate finish?