Features [Easy to use] The screw-in nut has an external thread and an All-en key, and is screwed in with an Al-len key [Easy to install] Insert nuts are better than barrel nuts and T-nuts because they can be installed from one side of the workpiece [Note] The depth of the pre-drilled hole must be equal to the length of the inserted nut plus the depth of any part of the bolt that may be screwed into the end of the nut of the workpiece [Multiple sizes] You can choose different sizes of screw-in insert nuts, and choose different screw sizes. [Sturdy and durable] This insert nut is made of a large amount of galvanized carbon steel, which has durability and rust resistance Description: An insert nut provides a threaded socket for a wooden workpiece, similar to a wall anchor. These insert nuts are inserted into a pre-drilled hole by screw in, in that case the external protrusions bite into the wood, preventing the nut from either turning or pulling out. Specifications: Material: Zinc plated carbon steel Type: Hex socket screw-in Thread Type (pitch): Coarse thread Size and Quantity( Optional) : M6*10mm     20pcs M6*13mm     20pcs M6*15mm     20pcs M6*17mm     20pcs M6*20mm     20pcs M6*25mm     20pcs M8*13mm     20pcs M8*15mm     20pcs M8*17mm     20pcs M8*20mm     20pcs M8*25mm     20pcs M10*25mm    20pcs Package Includes: 20pcs x Insert Nuts Package List