GREAT QUALITY: These insert nuts are made from high quantity zinc plated carbon steel material which provides strength and offers good corrosion resistance in many environments. > EASY TO USE: They are versatile threaded insert nuts that you can easily drive with them, easy to use. FEATURES: Insert nuts are advantageous over barrel nuts and to T-nuts, as they can be installed on one side of the room. MATCHING KIT: There are 6 different sizes of nuts (see detail size in description or photos) so so you can run your project for free. NOTE: The pre-drilled hole should be as deep as the length of the insert nut and any part of the bolt that can be screwed in beyond the end of the nut into the workpiece. Size and quantity (optional): M6*10 mm 20 pcs ( optional) M6*13mm 20 pcs(optional) M6*15mm 20 pcs(optional) M6*17mm 20 pcs(optional) M6*20mm 20 pcs(optional) M6*25mm 20 pcs(optional) M8 * 13mm 20 pcs(optional) M8*15mm 20 pcs(optional) M8*17mm 20 pcs(optional) M8*20mm 20 pcs(optional) M8*25mm 20 pcs(optional) M10*25mm 20 pcs( optional) Package Include: 20pcs x Insert Nuts Threaded Insert Nut Features: Material: Zinc Plated Carbon Steel Type: Hexagon Socket Cap Screws Package Include: 20pcs x Insert Nuts A insert nut provides a threaded socket for a wooden piece, similar to a wall anchor. These insert nuts are inserted into a screw pre-drilled hole, in which case the external protrusions bite into the wood, preventing the nut from turning or pulling out. Features: These insert nuts are made of high quality zinc plated carbon steel for durability and rust protection. Screw-in insert nuts have an external thread, and the hex socket is screwed with a hex wrench.