This is not a "heavy duty" shelf. It would be if the MDF shelves were thicker, but they are so thin that they bow in the center w/ very little on them. The company claims that each shelf can hold up to 800lb, for a total of 4000lb. That number is way beyond bogus! My shelves started bowing in the center as soon as I installed them, and looked like they were going to break appart w/ only 50lb on them! The connector brackets were also missing from the box, so I was only able to build 1/2 a shelf. I called the company's customer service and spoke to a lady that seemed like she dealt with this problem a lot, and said that they would send me out the brackets and "shelf supports". If they already have shelf supports designed to deal w/ this problem, why don't they come w/ the shelf?! They expect ppl to call them and complain first?
So, 2 weeks later, I still hadn't received the missing parts. I called, and the lady claimed that they had "just come in", and would be shipped out right away. She sounded like she had just forgotten. The brackets arrived, and although the connector pieces are the correct ones, the "supports" are just random metal brackets, that don't fit the shelf at all! They are too short to span the shelf, and are configured in a way that they wouldn't work even if they did. They sent me a bunch of metal pieces that I can't use, and I still have 2 shelving units that can't hold more than lightweight office supplies, when I bought them to hold heavy product inventory!!!