I have a Provari and iAtty. The iAtty screws fine onto the Provari. I can tell you that my setup fell out of my shirt pocket when I bent over to tie my shoe or something equally as stupid with a mod in my shirt pocket. The PV and iAtty hit the carpet at my feet. Thick carpet with a good pad so no scratches or scrapes on either unit.
When I picked up the PV and iAtty though I noticed that the iAtty was sitting cockeyed in the Provari. I was able to get them seperated "OK" but the PV threads being made of SS did a number on the PV threads. It will still tighten up fine but when they now screw together the connection is kind of wobbly until the last few threads and everything is tight again.
Guess what I'm saying is that the threads in a PV are softer than the threads in a SS 510 connection. I just now looked at my Provari and iAtty combo. No way the (male) threads on the iAtty are bigger than the (female) threads on the Provari. Sharper and able to damage the threads in the Provari, you betcha.
Repent
Edit:
I have a "stock" satin finish Provari less than a year old, and a "stock" iAtty.