A flow drill screw is provided, which includes a head, a threaded section of a rod, and a tip portion; the head is configured to connect with an external tool; the threaded section of the rod is configured for self-tapping a plate; the tip portion is configured to penetrate the plate; the threaded section of the rod and the tip portion are made of different metal materials, and ends of the threaded section of the rod and the tip portion are connected and fixed by welding. By using two different materials to make the threaded section of the rod and the tip portion, it can cope with different plates and meet different usage scenarios, and save costs. This design enables the screw to perform well under various complex conditions, thereby improving its applicability and reliability, and has significant economic and social benefits.

The invention relates to a method for connecting at least two elements by a connecting element. The method comprises the steps of: providing a first element, a second element and the connecting element; placing the connecting element on a surface of the first element; in a first time period, rotating the connecting element at a first rotational speed and exerting a first axial force on the connecting element in the direction of the surface of the first element; and in a second time period, rotating the connecting element at a second rotational speed and exerting a second axial force on the connecting element in the direction of the surface of the first element.

The invention relates to a method for connecting at least two elements by a connecting element. A first element, a second element and the connecting element are provided. The connecting element is placed on a surface of the first element. In a first time period, the connecting element is rotated at a first rotational speed and a first axial force is exerted on the connecting element in the direction of the surface of the first element. In a second time period, the connecting element is rotated at a second rotational speed and a second axial force is exerted on the connecting element in the direction of the surface of the first element.