19mm

19 millimeters (19 mm) is a length in the metric system. The millimeter is a unit equal to one thousandth of a meter, the base unit of length in the International System of Units (SI). Therefore, 19 mm equals 0.019 meters, or approximately 0.748 inches. Millimeters are commonly used for precise measurements in science, engineering, manufacturing, construction, and consumer products, especially when levels of precision better than a centimeter are needed.

In practice, measurements are often given to the nearest millimeter or tenth of a millimeter, depending on the required tolerance and the manufacturing process. The 19 mm dimension can describe many physical aspects, such as the diameter of a hole or rod, the thickness of a sheet, the width of a component, or the size of a fastener or its associated tooling. Industrial standards may specify exact tolerances and finishes alongside nominal dimensions.

Because 19 mm is close to three quarters of an inch, it is sometimes used as a reference for converting or communicating measurements in contexts where both metric and imperial units are encountered. The term also appears in product specifications, engineering drawings, and quality-control documentation where metric dimensions are preferred for consistency.

See also: millimeter, meter, centimeter, inch, metric system, unit conversion.