“A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away.” - Antoine de Saint-Exupery
Altho they are called "Ghostrivets" they are in fact screws.
The reason we have called them "Ghostrivets" is because in hoop construction, we are using them in place of the standard metal rivet (or even better - #Tinyrivets) that hold one end of the insert connection tube permanently. Once installed and 'finished' (by cutting the head off), they are almost invisible except for the outline of the screw in the hole, almost like a ghost.
The first 'version' of Ghostrivets were 4-40 3/16" slotted nylon setscrews. In order to function properly, they need to fit very tight in the hole. Using a 3/32" drill bit results in a tight hole for the ghost rivets. When installing, we found that due to the tightness (which is desired to retain the strongest fit) the amount of pressure applied by our metal slot screw driver damaged the head, sometimes to the point where complete insertion could not be assured.
So to make the Ghostrivet even better (because that's what we do), we gave the Ghostrivet 2.0 a larger 'socket' head which uses an allen wrench rather than a slot screw. The socket head allows for more torque to be applied resulting in a more secure insertion. We also extended the shaft a touch as well to allow deeper insertion prior to the removal of the socket head to finish the installation.
FAQ - "Don't the ghost rivets eventually fall out from the hoop bouncing on the pavement and such?" -
The ghost rivet is actually a miniature (threaded) bolt that grips both layers of polypro as it goes in. The fit is quite precise. The materials both have a small amount of 'give', so they tighten as they go in, sometimes so much that I use the allen wrench to do the final couple turns. At that point, it's very hard to 'turn out' with my fingers, so that gives you a sense of how tight the ghost rivet's grip is in the polypro. (The first version of the ghost rivet used a slot screw and when the rivet got well inserted, there was so much tension on the head from the slot screwdriver that the head tended to get distorted. That led us to add the larger hex screw head) So once the head is cut off, the only way the 'bolt' will come out is by drilling through it. The bolt and polypro are more 'compatible' than a metal rivet and polypro because they share more similar qualities (surface softness and more flexibility than metal) so the stresses are shared more harmoniously, ultimately resulting in less 'wear and tear' on the components and the connection as a whole.
Tiny rivets are great, but ghost rivets . . . .
you just don't see them at all. They do the same trick as a tiny rivet, but they are headless - they fiush