Spot welding machines can be classified based on the number of electrode heads, including single-head spot welding machines, double-head spot welding machines, and multi-head spot welding machines (also known as seam welders). Multi-head spot welding machines are typically used to weld mesh-like metal strips, forming a structure similar to a football goal net. Larger multi-head spot welding machines are also referred to as gantry mesh welders. The earliest company in China to introduce this type of equipment was Juntengfa.