17mm

17 millimeters is a unit of length in the metric system. It is equal to 0.669 inches and 1.7 centimeters. The value is commonly used to specify dimensions in engineering, manufacturing, and product design.

In mechanical engineering and manufacturing, 17 mm appears as a nominal dimension for features such as bore diameters, shafts, or the across-flats size of fasteners and nuts. It may be specified in drawings or tolerances, and tools such as wrenches or sockets sized for 17 mm exist to work with components of this dimension. While M17 is not a standard metric thread size, holes, bosses, or other features can be specified as 17 mm in engineered parts.

In photography and cinematography, 17 mm refers to the focal length of a lens. A 17 mm lens on a full-frame camera provides a wide-angle perspective suitable for landscapes, architecture, and interior scenes. On crop-sensor bodies, the effective field of view changes with the sensor size, yielding a somewhat different wide-angle character.

Beyond these contexts, 17 mm is used as a practical measurement in various consumer and industrial products, where precise small-scale dimensions matter. It serves as a reference point in tolerances, assemblies, and quality control for parts and hardware.