I just put my stools together.  They are quite heavy and sturdy.  I used a drill and drill bit to screw in the screws.  The Allen wrench was impossible to turn.  I followed recommendations from other reviews and they went in very well except for one screw which I will replace.  It seems too big for the hole!  One problem is that the edge of one seat was rough before painting, but they painted it anyway so it will snag clothing.  Thus I gave the 4 stars rating for screw and  rough edge!  They are well made, look great, and just the right size!