How are steel tubes represented?
If it is seamless steel pipe, welded steel pipe, the method of expression is: nominal diameter refers to the outer diameter (diameter * wall thickness). The unit is mm. [for example, seamless steel tubes of phi 32 * 3. It means that the nominal diameter (outside diameter) is seamless steel pipe of phi 32mm and wall thickness 3mm.
Galvanized pipe: InchSeamless steel tube, welded pipe, nonferrous metal pipe, etc.: outer diameter x wall thickness
If you speak of steel pipe, if it is water. Gas transmission pipe, then it is said: nominal diameter refers to the inner diameter. The units are millimeters or inches. [for example, water pipes with phi 25. It means that the nominal diameter (diameter) is 25mm (or an inch) steel pipe.
