almost all mobile phones will bend to varying degrees after being used for a period of time. The degree of bending depends on the size of the mobile phone. The larger the size, the easier it is to bend. The hardness of the material in the middle frame of the mobile phone, the softer the material, the easier it is to bend, whether it has fallen, whether the fuselage is pressed by external forces, and so on. I often say that Huawei's workmanship is poor (such as mate7), which means that Huawei's middle frame has poor hardness and is easy to bend. Bending the middle frame to a certain extent will endanger the screen security. For example, the relative deformation of Xiaomi 4 stainless steel frame is very small.