I know this
thread is a bit old, but I'm having the same problem the OP. I have to do almost a complete wrap around the coil screw to trap AWG 28 Gauge A1 Kanthal; even at that if I move it too much (like wiggling the legs to snap off under the screw) it pops out and I have to start from scratch. I'm fairly new to building, but it should NOT be this hard. It appears the bottom of my screws are semi rounded as well, hence all the trouble.
I have the
Kayfun Lite Plus V2 Dual Airflow Clone by EHPro, and I absolutely LOVE it, but the scres are driving me crazy.
Soo a Google search landed me here, and after some further reasearch I think I have found the answer:
Kayfun Screws - Knurled M1.6! I'm not quite sure though, becasue there is no slot for tightening with a tool, just the knurled tops for finger tightening... I tried a few google searches and coudn't come up with anything similar, but I did not try too hard. Maybe I'll dig around some more...
Anyhow, their
shop offers all sorts of nifty stuff for Russian/
kayfun originals and clones, and the shipping calculator on the cart page has reasonable shipping costs...
Hope this helps anyone else suppering from clone screw insanity...