256pcs Drilling Tail Screw Set, M4 Self Countersunk Screws, Tapping Head Drilling, Steel Screws for Metal Sheets Roofing Windows（7 Sizes）

1.【Quality Material】:The self-tapping screws are made of high quality galvanised iron. They have good rust, corrosion, heat, low temperature and other properties. The surface of the screws is shiny and the threads are clean. The material has high strength and can be used for a long time. 2.【Wide application】: Sheet metal screws with a flat head and cross recess are used in the household for furniture and appliances, machine tools, instruments, electronics, locks and lamps as well as for DIY work. In the commercial sector, they are suitable for mechanical engineering, steel construction and the assembly and maintenance of communication devices. 3.【Package Included】: The package contains 15 pieces M4.2*50mm, 25 pieces M4.2*38mm, 35 pieces M4.2*32mm, 35 pieces M4.2*25mm, 45 pieces M4.2*19mm, 50 pieces M4.2*16mm, 50 pieces M4.2*13mm Phillips screws, a Phillips bit and a storage box. 4.【Seven Sizes】: There are seven sizes of Phillips head flat head screws, so you can maximise the efficiency of the Phillips head flat head screws by choosing the right size according to the size of the object to be fastened. The screws of different sizes are arranged in a neatly organised storage box, making them easy to find and use. Prevents loss. 5.【Construction of the thread】: Self-tapping screws are sharp and hard and easily penetrate a variety of materials. 1mm threads are compact and uniform on the screw, making Tek screws less prone to deformation and slippage during use.