The main mechanism of the saw has three parts: the driving mechanism of saw blade, the feeding mechanism of saw blade and the horizontal movement mechanism of the saw which adjusts the ruler.

There are two driving modes of saw blade: direct driving by motor and via triangle belt or other driving modes. The former because of its high transmission efficiency, no - load energy consumption, large thermal saw are used in this way. However, in order to prevent the influence of thermal radiation on the hot rolled parts, protective measures must be taken. The motor of the second transmission mode is far away from the hot rolled piece, and the thermal radiation effect of the hot rolled piece is small, so special protective measures are not needed.

With the increase of output and cross section of rolled steel workshop, the thermal saw with sliding seat with longer working stroke and higher production efficiency is widely used in large and medium size steel workshops. In the early stage of the thermal saw with sliding seat, the feeding of the sliding seat was along the sliding way. Because the sliding way was worn fast, it was necessary to change the lining of the sliding way frequently, which was inconvenient for maintenance. In addition, when the slide is worn, the slide seat cannot slide straight forward, which increases the power consumption of feed and saw cutting and also increases the vibration amplitude of the hot saw during sawing. Therefore, China now USES the roller feed instead of the slide feed.