mounting rivets

[trplay]

I was pleasantly surprised to find two water bottle mounting screws on the right side of my Mushie seat frame.  These would really be nice for attaching a super lightweight seat if they ran up both sides of the seat.  How would one go about acquiring and inserting more of these mounting screws?

[jimali]

do a search on "threaded rivets"
appears the the better/stronger/heavier ones require a powered tool
I can find the "Pop Rivet" threaded aluminum ones I remember from some years ago.