I had nothing but grief assembling these items. What should have been an easy
fifteen minute procedure turned into a couple of hours. The holes in the arms and the frame for the screws holding them together are misaligned. With great difficulty I struggled to put the screws in at a sharp angle, hoping that they would somehow seat themselves. I wonder how long they can hold like that. 
Lousy quality control. I got a partial refund, which is insufficient.