PURPOSE: To uniformize spline gaps and to obtain the spline device of constant quality by subjecting a pipe member and shaft member to spline fitting, pressurizing the outer peripheral face of the pipe member in the direction that the spline gap becomes negative over the whole periphery and subjecting to plastic deformation a little.

CONSTITUTION: The inner peripheral face of a hollow drawing die 1 is made in specific tapered face 1a in the axial direction and the spline pipe 2 and spline shaft 3 subjected to spline fitting in advance are pushed in with axial directional force P. At this time, the pushing is executed until the axial directional force becoming in specific value within the range that the spline pipe 2 is not projected from the end at small diameter side of the drawing die 1 to pull out the whole body in the arrow mark F direction after subjecting the whole spline pipe 2 to plastic deformation. With this pipe 2 deformation, the spline of the pipe 2 inner periphery and that of the shaft 3 outer periphery are closely fitted almost on the whole but due to the elastic return in deformation at the time when the pipe 2 is pulled out of the drawing die 1 being nearly constant, the clearance through splines is aligned to reduce the dispersion in the gap of the spline fitting.