👉 A marler is a type of metalworking tool used to shape and polish metal surfaces. It consists of an iron rod, which is heated to a high temperature, and is then placed on the surface of the workpiece. The heat from the heated iron rod causes it to harden and become smooth, while also allowing for precise shaping and polishing of the surface. Marlers are commonly used in the metalworking industry for tasks such as engraving, painting, and cutting.