Thicker, Stronger Brackets - Heavy Duty - 1/4" Thick (6mm) You don't have to settle for thin 5mm weak brackets that cause poor shelving. Our 1/4-inch-thick brackets will safely hold more weight and are sturdier than any other open lip brackets on the market. Made to perfectly fit nominal size 1" x 8" and 2" x 8" dimensional lumber boards found at local home stores. Simply attach a wood plank on top of these floating shelf brackets and you've got a beautiful rustic looking shelf. Manufactured from solid 6mm thick metal with a strong durable matte black powder coat finish, our durable iron shelf brackets are simply made to last.