This office chair is impossible to assemble. The mounting screws used for the steel plate, the key part that connects the the chair back to the chair base, cannot properly go in straight given the pass-through holes in the steel plate are too small, and the screws don't fully align with the screw areas. You end up with screws jutting outward,  or are not able to full screw into place. I have a screw that can only go a quarter-inch in.  And then you have a loose feeling chair.