Differents between Tube and Pipe for 304/316L stainless steel.

When I enter into the business of the stainless steel tube/pipe production as a beginner, I did not noticed the letter of “PIPE” and “TUBE” have the different identity. Someday, when I compare the size of standard ASTM and NPS, I find some different and confused in abruptly. So if you have the same doubts as me, hope it is helpful for you.

Shape:

Pipe is round section but tubes can come in different profiles like square, rectangular, oval and other irregular shape. So looking from the shapes, tube has included the pipe.

Dimension:

Pipe is measured using schedule and the inside diameter of material, it often described as size 2” with SCH 40, meaning ID 60.3MM and 3.91MM thickness. OD should be ID+ THICKNESS.

While tube is measured by outside diameter and wall thickness of material. It often described as size of OD 2” with the thickness. The measured methods is different. Tube size is non-standard size but pipe not.

Application:

Tubes are often used for structural purposes, such as in construction, automotive frames, and furniture. They can also be found in applications requiring precise outer dimensions, such as heat exchangers, instrumentation systems, and hydraulic systems.

Pipes, on the other hand, are commonly used for conveying fluids, gases, or solids. They are widely used in industries such as oil and gas, water supply, plumbing, and drainage systems.