MADE OF SPHC STEEL-SUPPORT 90LBSShelf bracket are made of SPHC steel, which is stronger than ordinary steel. When properly installed on the wall, a pair of 3mm thick heavy duty steel brackets for shelves with high strength screws carry up to 90lbs (If you want to load more, you could use more brackets for floating shelf). With high-temperature black painting surface to prevent rust and corrosion, which can make floating shelf bracket more durable. Install once, use for life. INVISIBLE AFTER INSTALLATION & WIDELY USEDInvisible but sturdy,minimalist and modern style. The corner brace is only 0.78 inches high so can easily conceal between the wall and shelf. Once installed, these triangle shelf brackets are completely invisible, creating the illusion of floating shelf. Easily mount your brackets in your home office, bathroom, living room, kitchen, dining room, bedroom, garage, under stairs or even front porch.Make your home more comfortable and visually pleasing. PRODUCT SIZE & PERFECT FITThe size of shelf brackets: 5.5"x5"x 0.86", with a thickness of 3mm. This black brackets for shelves fit the nominal 6" to 9" W with 0.9" to 1.1" H board. Included hardware: 4 x Black shelf brackets, 13 x Long Screws, 9 x Short Screws, 13 x concrete anchors, 13 x drywall anchors, 1 x Bubble Level. COUNTERSUNK SCREW HOLE & ONE-PIECE MOLDINGIndustrial shelf brackets 6 inch have been upgraded with countersunk screw holes compared to others brackets, the nails will not stick out after being installed. The surface of shelf bracket is completely flat, no gaps between the heavy duty shelf brackets and wood plank after installation. One-piece molding process makes shelf brackets heavy duty more solid. And the smooth edges meaning no sharp edges for you to hurt yourself. EASY INSTALLATION Installation steps: 1.Dig holes on the wall and board, then install the screws 2.Tighten screws with a screwdriver. No special skills are required to mount wall brackets for shelf. If you have any problems, Please feel free to contact us. We offer 90days no reason refund or offer new free replacement guaranteed, welcome to by write us email for more help.