Hollow Structural Steel Tube, also known as heavy wall steel tube, is essentially a thick-walled steel tube made by rolling steel plates. It is primarily used in industries such as hydraulic cylinder production, billboards, engineering pillars, and large shaft processing. The wall thickness of the rolled steel tubes typically ranges from 6 to 20mm, with the cold rolling process extending it to between 20 and 35mm.
Thick-walled steel pipe, typically referring to steel pipe sheets with a wall thickness of 45mm or more, sees an increase in strength and hardness as the wall thickness increases. Using cold rolling methods can easily lead to material damage and signs of cracking. Therefore, hot rolling methods must be employed for such thick-walled steel pipes. This involves heating the steel plate as a whole before rolling and welding it, rotating it into shape within the rolling machine, welding it to the desired length, and then performing a weld inspection. After removing the weld reinforcement, the pipe is inspected for quality before being dispatched.

Steel plate coiled thick-walled steel pipe
Large-diameter plate and coil thick-walled steel pipes are commonly used, as the force during rolling is significant, they are typically rolled to 1.8-2.5 meters before being joined to the length required by the customer. This method is also known as the T-welding technique. The materials for thick-walled plate and coil steel pipes can be selected from Q235B, Q345B, Q345C, Q345A, 16Mn, etc. 45# or high-alloy steel is less common due to their strength.