A group of us at forums.anandtech.com have had no success whatsoever with these so-called Fan "Screws".
Our attempts to pull them thru any normal fan mounting hole are met with either failure or destruction of the rubber pin no matter what lubricant is tried. My conclusion is that the rubber is either much too hard for the purpose (perhaps if we tried them at over 100 degrees, they might work) or the design is wrong for the material used.
Please chime in with your experience.
P.S. Moderator, please consider a sticky. Thanks.bh.