I've been going down the rabbit hole as far for pipe vs tube and have ran into the same statement from co-workers and on the internet. That statement is
"TUBE IS STRONGER THAN PIPE" https://www.metalsupermarkets.com/difference-between-pipe-and-tube/
Which makes no sense to me, shouldn't how strong they are be a function of wall thickness and pipe ID? It seems like it's just comparing apples and oranges. Anybody got some insight on this ?
Firstly, I assume that when you say "tube" what you mean is Hollow Structural Sections, and when you say "pipe" I assume that you mean typical scheduled pipe sections.
In the US, the AISC Code specifies material properties for structural shapes. From the manual Tables 2-4, we can see that the Pipe material is ASTM A53 Gr. B, and that for round HSS we have ASTM A500 Gr. B as the most common shape.
These two materials are characterized by their yield and tensile stresses.
For A53 Gr. B, Fy = 35 ksi and Fu = 60 ksi. For A500 Gr. B, Fy = 42 ksi and Fu = 68 ksi.
Not only is the pipe wall thickness and pipe ID/OD part of the strength of a given element, but also the Material Strength plays a large roll.
Your intuition that the wall thickness and ID/OD effect the strength is correct. But if you have a pipe with identical dimensions as an HSS tube. The HSS(tube) will be stronger because it has higher Fy and higher Fu.
The advertisement referenced in the question was written by a liberal arts major without much of a clue what he was writing about. Pipe comes in certain diameters and wall thicknesses and threads defined by ANSI OR API ( in the US, code bodies in other countries usually follow these same sizes - such as CSA in Canada). Pipe and tube may be made of the same material so to say one is stronger is nonsense. Tubes may be square and other shapes. ASTM writes the specifications for pipe and tube ( in the US ). Although there are 2 separate committees ( 10 and 11 if I remember correctly) about 80% of the people are on both committees. For clarification : API has specifications for pipe, casing, and tubing . API pipe is essentially the same sizes as ANSI pipe but is likely different steels. API casing and tubing is very specific to oil/gas wells and rarely used elsewhere.
The toughness of a material only has to do with some of its properties.If the tube and the pipe are made from the same material and then they would have the same toughness.
Given pipe and tube of same material/strength properties, the manufacturing tolerances also matter. HSS has higher standard to meet thickness properties, whereas pipe can vary up to something like 7% of the nominal thickness. so, yes your wall thickness can be 0.45" on a 1/2" wall pipe.
