centretocentre
Center-to-center distance, often abbreviated as center-to-center or c-to-c (sometimes written as C-C or c-c), is the straight-line distance between the centres of two features, such as holes, shafts, or mounting interfaces. It is a fundamental dimensional specification in mechanical design and fabrication, critical for ensuring proper alignment, fit, and function of assemblies.
In technical drawings, the center-to-center distance is shown as a linear dimension between two center marks.
Applications and calculations: In gear trains, the center distance between two gears with pitch diameters d1
Tolerance and quality considerations: Center-to-center dimensions are often tightly controlled to prevent misalignment, binding, or uneven
Limitations: The c-to-c distance specifies only the linear spacing between centers; it does not define orientation