Dimensions and weights of tubing

Tubing is measured according to three main dimensions other than length. The outside diameter (O.D.), the wall thickness (W.T.)

It is important to note that a pipe is usually measured by its Nominal Pipe Size (NPS). This size is related to the outside diameter, but varies widely in specifications. A tube is ordered by its outside diameter and wall thickness, while pipes are ordered by nominal pipe size, nominal diameter and schedule number or wall thickness.

Tubing & Instrumentation

Tubes are widely used in instrumentation in a variety of industries, including oil and gas, chemical processing, power generation and pharmaceuticals. Instrumentation tubes are crucial for connecting instruments, valves and other devices in systems designed to measure, monitor and control process variables such as pressure, flow, temperature and level.

Tubing Size Charts (BWG/SWG)

BWG (Birmingham Wire Gauge) was originally developed to measure wire diameter, but has long been used to specify pipe wall thickness. The Birmingham gauge is also known as the Stubs iron wire gauge or Birmingham wire gauge. It is not the same as, but is similar to, the Stubs iron wire profile. BWG is primarily used in the United States and is more common in industries involved in pipe and tube manufacturing, especially for boilers, heat exchangers and other metallic tubing.

SWG (Standard Wire Gauge), like BWG, was originally developed to measure wire diameter, and it is more widely used in the United Kingdom and other Commonwealth countries. It is used in several industries, including jewelry making, wire manufacturing and tubing, especially in the electrical sector. Like BWG, a lower gauge number in the SWG system means a thicker material. However, the actual thicknesses defined by SWG numbers differ from those in the BWG system for the same gauge number.

BWG tubing dimension & weights

SWG tubing dimension & weights