The article "Involute Splines" appeared in the September/October 1990 issue of Gear Technology.
Engineering design requires many different types of gears and splines. Although these components are rather expensive, subject to direct wear, and difficult to replace, transmissions with gears and splines are required for two very simple reasons: 1) Motors have an unfavorable (disadvantageous) relation of torque to number of revolutions. 2)Power is usually required to be transmitted along a shaft.
The article "Involute Splines" should appear in the box below, but if you do not see it, you can download it here.