The spline shaft has a longitudinal keyway on the outer surface of the shaft, and the rotating parts on the shaft also have corresponding keyways to maintain synchronous rotation with the shaft. While rotating, some can also perform longitudinal sliding on the shaft, such as shifting gears in the gearbox.

There are many processing methods for spline shafts, mainly using cutting methods such as rolling, milling, and grinding, as well as plastic deformation processing methods such as cold stamping and cold rolling.

Rolling cutting method: Use a spline hob to machine on a spline shaft milling machine or gear hobbing machine according to the generating method.

Milling method: On a universal milling machine, use a specialized forming milling cutter to directly mill out the contour between teeth, and use a indexing head to divide the teeth and mill them one by one; If a forming milling cutter is not used, two disc milling cutters can also be used to mill both sides of a tooth at the same time. After milling each tooth, a disc milling cutter can be used to slightly adjust the bottom diameter.

Grinding method: Use a formed grinding wheel to grind the side and bottom diameter of the spline teeth on a spline shaft grinder.