Use
Pipe：The main purpose of pipe is to transport gas and liquid. Its core value lies in the size of the internal space and how much fluid can pass through it.
Tube：The pipe is mainly used in structural applications, such as support frames, etc. Its core features are shape, hardness, etc.
Size
Pipe：When purchasing a pipe, you should mainly pay attention to its inner diameter and wall thickness, because the main function of the pipe is to transport fluid, and the inner diameter of the pipe determines how much fluid can pass through.
Tube：The key dimensions when purchasing tubes are the outer diameter and wall thickness, as they are primarily used in structural applications where the outer diameter of the tube determines its size and the wall thickness determines its stiffness.
Wall thickness standard
Pipe：The wall thickness of the pipe can be determined using Schedule, SCH10, 40, 80, etc.
Tube：The wall thickness of the tube is very precise, so the wall thickness of the tube must be measured and sch cannot be used.
Shape
Pipe：Since its main function is to transport fluid, round is the most suitable shape for transporting fluid, because the round shape can evenly withstand the fluid pressure, so pipes are almost all round.
Tube：Tube is not so demanding in terms of shape, it can be round, rectangular and other shapes.
Shape tolerance
Pipe：The pipe has a relatively loose dimensional tolerance requirement because the shape is not important for its use, the main thing is the pressure bearing capacity and sealing.
Tube：The tolerance requirements are very strict and the shape requirements are very high.
Connection method
Pipe：Pipe connections will use sealed and standardized thread, flange, welding and other methods
Tube：There are many ways to connect, such as crimping, flaring, brazing, precision welding, etc. Some tubes do not need to be connected and can be used directly for support.
Material
Pipe：Pipe materials are preferably carbon steel, stainless steel, PVC, etc.
Tube：Tube materials are mostly copper, brass, aluminum, stainless steel, carbon steel, etc.
Cost
Pipe：Pipe is usually cheaper than Tube and is sold by length or weight.
Tube：Tube is more expensive and is usually sold in finished lengths.
