According to DIN 5480, the centering of the splines are classified based on the spline
functioning to transmit the torque and for centering the rotor to the shaft.
- Flank-centered connection: The flanks of the teeth serve to transmit the forces as well as to center the hub and shaft relative to one another. The fit and the centering accuracy are determined by the deviations of the space widths and thicknesses as well as by the tolerances achieved or specified.
- Diameter centered connections: The teeth merely serve to transmit the forces. The fit and accuracy of concentricity are determined by the selected ISO tolerance fields of the centering diameters.
- Outer diamter centered: Diameter-centered connections which are centered on the outer diameters (hub root circle diameter and shaft tip circle diameter = outer diameter centering)
- Inner diameter centered: Diameter-centered connections which are centered on the inner diameters (hub tip circle diameter and shaft root circle diameter = internal diameter centering)
The tolerance fields, nominal dimensions of the centering diameters and limits of centering accuracy are described in DIN 5480:2006 part 1.