Features These insert nuts are made of highly galvanized carbon steel for durability and rust protection. Screw nuts have an external thread and internal hex drive and are screwed with an Allen wrench Insert nuts have the advantage over cylindrical nuts and T-slot nuts in that they can be installed on one side of the workpiece. Screw nuts come in different sizes and fit different sizes of screws you can choose for your project The pre-drilled hole should be as deep as the length of the insertion nut plus the part of the screw that can be screwed into the workpiece beyond the end of the nut. Description: An insert nut provides a threaded location for a wooden part, similar to a wall anchor. These insert nuts are screwed into a pre-drilled hole. The outer protrusions grip the wood and prevent the nut from turning or being removed. Features: These insert nuts are made of highly galvanized carbon steel for durability and rust protection. Screw nuts have an external thread and internal hex drive and are screwed with an Allen key. Insert nuts have the advantage over cylindrical nuts and T-slot nuts in that they can be installed on one side of the workpiece. Screw nuts come in different sizes and fit different sizes of screws you can choose for your project. The pre-drilled hole should be as deep as the length of the insertion nut plus the part of the screw that can be screwed into the workpiece beyond the end of the nut. Specifications: Material: Galvanized carbon steel Type: Screw-on hex socket Thread type (step): coarse thread. Size and quantity (optional): M6 x 10 mm, 20 pieces M6 x 13 mm, 20 pieces M6 x 15 mm, 20 pieces M6 x 17 mm. 20 pieces. M6 * 20mm 20pcs M6 * 25mm 20pcs M8 * 13mm 20pcs M8 * 15mm 20pcs M8 * 17mm 20pcs M8 * 20mm 20pcs M8 * 20mm 20pcs M8 * 25mm 4 in 20 Pieces M10 x 25 mm 20 Pieces Package includes: 20pcs x Insert Nuts Package List