There are many kinds of welding machines, including single point single function, single point dual function and single point multi-function (this kind of welding machine also has only one welding head, and can weld at any angle between 90 ° and 180 ° after changing the form of the positioning plate). There are also two point, three point, four point and even six point welding machines and four corner welding machines. Different types of welding machines have different welding functions and work efficiency.