Is this what you have?
or this one:
The first one is a standard barbell, it probably weighs around 20 lbs and its 1 inch wide all the way along, I have one of these from my early years and my guess is it can't hold more than 350 lbs and that being a longshot. It would probably break since the screws are so small and look so fragile.
The second one is the olympic barbell, and the guys above me have already given a nice input on the subject
