These are commercial bar stools, and so they are heavy duty. That's just what we needed. They are comfortable too. 
We got two. My husband uses them in his game room, and he loves them. 
If it seems like the hardware is missing, take a look in the creases of the box. That's where our hardware was hiding. 
As to the assembly: this stool is very easy to put together. There are only two parts - the legs and the seat. Just be sure to balance the upside-down seat on a pillow (or something else) so that the holes of the seat are level to the floor. Then place the upside-down legs on the upside-down seat and line up the holes perfectly. The holes are a little hard to see - so look carefully. Then fit the screws into the lined up holes, and screw them in with the enclosed allen wrench. Easy-peasy. I'm a seventy-one year old woman, and I put these together lickety-split.