SIMPLE TO USE: The screw insert nuts have an external thread and a hexagon socket drive and are screwed with a hex wrench. EASY INSTALLATION: These hexagon socket screw insert nuts are advantageous over nuts barrels and T-nuts, as they can be installed from one side of the room. CONVENIENT TO USE: The pre-drilled hole should be as deep as the length of the insert nut plus any part of the bolt that can be screwed past the end of the nut into the workpiece. PREMIUM MATERIAL: These insert nuts are made from a high quantity zinc alloy and come in a resealable clear plastic box. Different Sizes: This screw nut set comes in different sizes and takes different sizes of screws. (M410mm, M510mm, M610mm, M615mm, M820mm, M1025mm) Description: A insert nut provides a threaded socket for a wooden piece, similar to a wall anchor. These insert nuts are inserted into a pre-drilled hole by screwing, in this case the external protrusions bite into the wood, preventing the nut from turning or