ThePipingMart Blog other The Difference between Tube and Hollow Bar

The Difference between Tube and Hollow Bar

Tube: Tube is a popular choice in industrial sectors due to its remarkable strength. It is available in a variety of shapes such as square, rectangle, and round. The tube has a wall thickness that is measured in fractions of inches. The tube is measured by its outer diameter.
Hollow Bar: Hollow bar has a similar shape to a tube, however, it has more wall thickness. The hollow bar is lightweight and has the strength of a solid bar. It is a popular choice due to its cost effectiveness with higher strength. It is easily machineable both on the outside and inside. The hollow bar is measured by its inner as well as the outer diameter. Following parameters are considered while differentiating between the tube and hollow bar.

Fabrication Process:

There is a difference in the manufacturing process of Tube and Hollow Bar. A tube is developed by running a slit coil of base metal through a tube mill to get the desired shape. A tube is formed in different shapes like square, round and rectangular. Using electric resistance welding, the edges of the tube are welded together after getting the desired shape. A high frequency welding is also used during the development of tubes. A welding process is based on the type of material and desired thickness. Also, the preference of the manufacturing team also matters while selecting a welding method. After the welding process, excess material is removed. An annealing process is used to get the refined quality of the tube.
The big difference in the manufacturing process of tube and hollow bar is, the welding process is not used while developing a hollow bar. There are two processes to create this bar which depend on dimensional requirements and the type of material used for the fabrication. One of these processes is drilling which includes sending a drill through a solid metal bar. This method offers precise dimensional accuracy which is essential in many critical applications. Another method used for the development of Hollow Bar is Centrifugal Casting. In this process, round mold undergoes high speed rotations, and molten metal is poured into a cast. Due to high speed rotations, the metal is forced outside the frame. Here it gets cool and hardened that creates dense and desired results in the form of Hollow Bar. Hollow bar is developed using stainless steel and bronze only.

Qualities and Features:

A Hollow bar possesses more tight dimensional tolerance compared with the tube. It is more difficult to get the required tolerance with the tube. The quality of the tube depends on the welding process during the fabrication. So to get the desired results, utmost care should be taken during welding. An excess material after the welding process of the tube should be removed in order to prevent the stress concentrators. To get a uniformed structure of tube, it should be heat treated or annealed after the welding process. There are different structures created during the welding that can affect the mechanical properties of tubes.

Materials used for the fabrication:

A tube can be formed using a wide range of materials that possess good electrical conductivity. An electric resistance welding process is used for welding. A hollow bar can be formed using all types of materials. The materials that have hardness are more difficult, so a piercing method is used in the development process. A type of material for the tube and hollow bar is based on the applications. A hollow bar is considered cheaper than a tube so are widely used in the industries. While selecting between tubes and hollow bar different parameters are taken into consideration, such as tolerances, design, and material type.

Related Post

The Difference between Tube and Hollow Bar

by Piping Mart time to read: 2 min