How is pipe measured compared to tubing?

Pipe and tubing have distinct measurement conventions that reflect their respective applications and material specifications. For piping, the measurement is typically taken on the inside diameter. This is important because the inside dimension determines the flow capacity of the pipe, which is critical in plumbing and fluid transport systems.

On the other hand, tubing is measured based on its outside diameter. This measurement is essential for ensuring the proper fit with connectors, fittings, or other components in applications such as structural frameworks or hydraulic systems, where the outer dimensions affect alignment and attachment points.

Thus, when comparing how each is measured, it is accurate to say that pipe is measured on the inside, while tubing is measured on the outside. Understanding this distinction is crucial for ensuring that the correct dimensions are used for specific applications, thus avoiding potential installation or functionality issues.