All pipe weights with the same nominal pipe size have the same:

When discussing nominal pipe sizes, it's important to recognize that all pipes designated with the same nominal size are standardized to have the same outside diameter. This is a critical aspect of piping systems, as it ensures compatibility when connecting different lengths of pipe and fittings.

The outside diameter remains consistent across various materials and wall thicknesses, allowing for uniformity in the design and installation of piping systems. Even though pipes may have different wall thicknesses and, consequently, different inside diameters and mass per meter, they will all share the same nominal outside diameter as per standardized dimensions.

This consistency allows engineers and installers to easily select compatible components within a piping system, facilitating effective assembly and maintenance.