73mm

73 mm is a metric measurement referring to a length or diameter of 73 millimeters. It equals 0.073 meters or about 2.874 inches. In technical contexts, 73 mm is used to express the bore diameter of firearms or artillery, as well as the external diameter of cylindrical components.

In engineering and manufacturing, 73 mm is a common dimension for components such as holes, shafts, flanges, pipes, or machine parts. It appears in specifications, tolerances, and drawings where a precise, decimal-based measurement is required. Depending on the application, tolerances around this size may range from a few hundredths to a few tenths of a millimeter.

In military and historical contexts, calibers described as “73 mm” denote the internal bore diameter of guns or anti-tank weapons. Caliber-sized designations were used by several nations in the mid-20th century for light field artillery and anti-tank guns. Today, such pieces are largely out of front-line service, though they may be found in museums or historical references.

In optics and photography, 73 mm can refer to a front-diameter or filter-thread size for lenses or accessories. While the most common filter sizes tend to be 72 mm, 77 mm, or 82 mm, some lenses or special-purpose equipment adopt a 73 mm diameter.

Overall, 73 mm is a practical, non-specialized dimension that appears across multiple domains, typically requiring precise manufacturing and measurement practices in professional contexts.