These bi-fold door hinges are constructed of steel and come in a matte black finish. They feature a non-mortise design allowing them to be easily mounted on the door's edges, avoiding the need to chisel and mortise for installation. For best results, use a 3/32 inch bit to drill pilot holes prior to screwing in fasteners to avoid splitting wood. These door hinges are used on bi-fold doors by a variety of wardrobe manufacturers.