These bi-fold door hinges are constructed of steel and come in a nickel plated finish. They feature a non-mortise design allowing them to be easily mounted on the doors edges, avoiding the need to chisel and mortise for installation. For best results, use a 3/32 in. 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.