Features: Make of Zincs Alloy, high hardness, and good wear resistance, standard inner hexagon socket, smooth. Suitable for connection and fastening of various objects, often used in furniture cabinets, wardrobes, and connecting plates. Inner hexagon head with flanges, evenly stressed on the inner and outer thread teeth, and the structure are more stable. Installation: The mounting hole should not be larger than the outer diameter of thread. When the nut is locked, some wood glues can be apply to the outer teeth to make the fastening effect good. This set of screw in insert nut come in different size and take different screw size. Specifications: Materials: Zincs Alloy Size: As Shown in the Picture Package Includes: 20Pcs 4x10mm 10Pcs 5x10mm 10Pcs 6x8mm 10Pcs 6x10mm 10pcs 6x13mm 10Pcs 6x15mm note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.