I rated Ease of Assembly & workmanship very low because of the problems I had but if things had worked correctly it would have been a 4 or 5 on ease of Assembly. I bought 2 of these chair (matching set for 2 workareas) . 1st one went together in about 20 minutes, 2nd one I could not get 3 bolts to go in the holes. Returned and re-order, this one the tension knob was broken when it arrived(box was ripped also but wasn't home when delivered so couldn't reject it), So Overstock sent another and I had the same problem as the 1st one the bolts/screws wouldn't go in(exact same ones as the 1st). I went to the hardware store this time and bought new hexigon bolts(instead of the screw type that it came with... These finally went in with a wrench. Now that they are together they look great in my new office.