Michigan Automatic Turning Inc. Transmission Shafts & Gears Spline Rolling Michigan Automatic provides spline rolling, CNC milling and grinding, hobbing and many other machining... services for shafts and gears. Why Spline Rolling? Rolled splines are stronger and cheaper than hobbed splines. A spline that takes 10 minutes to hob can be rolled in 15 seconds.... This translates to tremendous cost savings with no loss of accuracy or strength. Indeed, because rolled splines increase grain structure density and reduce stress concentration...