GB/T 1566-2003

This standard specifies the dimensions and tolerances for square and rectangular cross-section keyways used in thin keys. It is applied in mechanical engineering for designing and manufacturing key connections in shafts and hubs, particularly in applications requiring shallow keyways to minimize stress concentrations or accommodate limited material thickness. The standard ensures interchangeability and proper fit in light-duty power transmission systems, such as in small motors, pumps, and precision machinery.