The diameter range of steel bars that can be welded by the hob-welder is usually 4mm to 16mm. There may be some differences between different models of seam welders, and the specific welding diameter limits may vary depending on the specifications and design of the equipment. When selecting a hob-welding machine, it is necessary to determine the appropriate equipment according to the specific engineering requirements and steel bar specifications. In addition, the diameter of the steel bar will also be limited by other factors, such as the material and strength of the steel bar. When welding steel bars, it is necessary to ensure that the quality and specifications of steel bars meet the relevant standards and requirements to ensure the quality and safety of welding.