There are springs on them, they would not work without them. The pins need to be held back when you attach it to the spool hub. It has two holes & connecting slots on the hub for the heads of the pins inside the ring to lock into. It looks as though there are none though!
I simply used 1/4" 20 fillister screws & turned the heads down to fit the lug holes in the spool.
I used a flanged nut & red loctite to secure it after inserting the spring.
As far as doing away with the threads on the screws, I am thinking on that now. :-)
I'm thinking shoulder bolts may be a very good solution. I could make the collar ID a little thicker too, by using thicker material, I just lucked across these. Just faced one end, bored the ID out .110" larger & drilled two holes 180 degrees apart.
The miller parts are molded & there's a thick tab where the pin goes thru, providing more stability for it. The threaded screws tend to move around a bit, but by far, a quick & inexpensive solution to the problem :-) S.W.