Heavy Duty Floating Shelf Bracket with Heavy Loading Capacity. Our countertop support brackets are made of premium iron that can hold heavy weight well. Apart from the thick steel, the two pieces of steel are solidly welding together to ensure its security. The countertop metal brackets can hold about 100~200lb per pair. With the floating wall bracket, you can make the most use of your wall space and store more items. It is an easy and affordable way for countertop support.