The Stubs Iron Wire Gauge system (also known as the Birmingham Wire Gauge) is used in medicine to measure the diameter of hypodermic needles, catheters, and suture wires. It was originally developed in early 19th-century England for use in wire manufacture, and it began appearing in a medical setting in the early 20th century.
The Stubs system was the first wire gauge recognized as a standard by any country when Great Britain adopted it in 1884. Each gauge increment roughly correlates to multiples of .01 inches, but the system is not truly linear, as can be seen in the Needle gauge comparison chart. Also, the needle gauge is inversely proportional to its diameter, so the larger the gauge number, the narrower the diameter.
ISO 9626: Stainless steel needle tubing for the manufacture of medical devices, 1st ed. Geneva: International Organization for Standardization, 1991: 1–2.
ISO 9626: Stainless steel needle tubing for the manufacture of medical devices, Amendment 1. Geneva: International Organization for Standardization, 2001: 1–2.
