Second step from first end is splined
A shaft having two or more different diameters (greater than 0.031 inches (0.79 millimeter)) along its length. It must have one or more of the following conditions: a specified surface finish designation in the range 1 to 125 microinches (0.025 to 3.2 micrometers) arithmetical average (aa), machined peripheral flat(s), circular groove(s), keyway(s), splines, threads, or holes. The ends and/or shoulders may be machined to accommodate bearings, couplings, and the like. It is not designed for use in aligning by fitting into corresponding holes of another item. For items used to support rotating members see axle(1), shouldered. For items not having any of the above conditions see pin, shoulder, headless. Excludes shaft(1), straight; and axle(1), straight.
Classification: Transmission shafts and cranks, except camshafts and crankshafts
NSN 5935-01-112-3634
NSN 5835-00-867-0291
NSN 6685-00-551-3285
NSN 5950-00-343-1910
NSN 5910-00-143-0851
NSN 2925-00-246-3077
NSN 6220-00-751-9709
NSN 5855-01-317-5354
NSN 5905-00-241-5643
NSN 5835-00-998-5757
NSN 5960-01-407-1350
NSN 6685-00-276-9889