Features: *【Quality Material】: These screws are made of high quality carbon steel with a beautiful silver finish. The carbon steel material has great hardness and toughness, making it an excellent mounting material. *【Effective and Practical】: Good expansion effect, fixed installation, spiral thread, uniform, not easy to rotate. Exquisite workmanship, simple structure, easy installation and use ensure a perfect effect. *【Easy to use】: It can be used like ordinary bolts and nuts - screw the screw into the part to be fixed, then fix the nut and it into the screw. When turning, the nut opens gradually, further increasing the attachment area. *【Wide Application】The petal nut is perfect for DIY or construction projects as it can be used with a variety of materials, including plastics, plywood, hollow walls, iron sheets and more. *【Package includes】: A set of 20 push off screws. The nuts of these bolts are unique flared nuts that inflate when tightened, increasing the attachment area. Ideal as a fixing screw for thin plates. Specifications: *Product Name:Expansion nut *Color:silver *Material:steel with zinc plating. *Size:4*16，4*20，M5*20，M6*20 Package Content: 20pcs Expansion nut Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data.