Steel shelves are used in manufacturing facilities for storing items. I have seen steel shelves in our company store and shop floors in the company where I used to work.
In store department they have used steel shelving. They had also closed shelving for storing expensive items.
These shelves are made of traditional 18-22 gauge steel. Take a look here. You will see different types of steel shelving products.
HALLOWELL HI TECH MEDIUM DUTY OPEN SHELVING is ideal for small warehouses and small companies.
The product has been designed in such a way that people can assemble it quickly. It can bear 500 pounds weight per shelf.