Tubes may be considered extensions of sheets by way of shape. They are essentially made from sheets by rolling to the shape and welded at the joint. Besides processing the characteristics of HRCA and CRCA sheets as discussed earlier, the mechanical characteristics of tubes increase tremendously because of the increase of bending moment of Inertia. “Strength to weight ratio is better for a hollow pipe than a solid rod.”

Difference Between Pipe and Tube


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Pipes are always round-shaped, while tubes can be rectangular, square, or round. Pipes are specified with a nominal diameter which is the inside diameter, and a “schedule,” which means the wall thickness. Tubes are specified in terms of outside diameter if it is round, or the dimensions if square or rectangle, and the wall thickness. Generally, speaking pipes are meant for piping works to transfer fluids and gasses, while tubes are used in structural constructions. Both pipes and tubes may be seamless or welded. Both are available in the galvanized state.

A Façade constructed with Hollow section Tubes.
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A Designer Table.
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Typically available in sizes:
PRODUCT	SIZE mm	TH mm	LENGTH Mts
Round Tube M.S Black	NB Dia 15 up to NB Dia 150	2.0 5.4	6.0 to 18.0
Round Tube Structural Purpose	NB Dia 15 up to NB Dia 350	2.0 12.0	6.0 to 18.0
Rectangular Hollow Section (RHS)	40*20 up to 240*120	1.2 8.0	6.0
Square hallow Section (SHS)	19*19 up to 180*180	1.4 8.0	6.0

An art installation using steel tubes. (Image source)

Tubular forms remain rigid without depending upon other support structural elements.