Tapered thread bowden coupling PC4-M10 or PC4-M11? (For my FLSun 300x300x420 2018)

For some strange reason krtektm's https://www.thingiverse.com/thing:1993384 10mm threads just slipped inside my FLSun Clone E3d V6 clone...

I increased those thread widths and magically, it threaded on the first attempt. I have no idea what size they are now. Possibly 10.5 or 11?

Anyway, I also removed the hex because it didn't slip through my X-Carraige mounting hole.
I STILL had to DREMEL out my mounting hole a bit but it works for me :-P

If you clean out the "clamp" / "compression