2nd step on 1st end splined, largest diameter flatted 2 sides
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 5925-01-078-6673
NSN 5960-01-249-4550
NSN 5910-01-056-8549
NSN 5855-00-885-8452
NSN 5985-01-027-9122
NSN 5950-00-248-6921
NSN 5935-00-245-8789
NSN 5925-01-659-2618
NSN 5920-01-557-7552
NSN 5975-01-459-7763
NSN 5910-00-194-0380
NSN 6135-01-115-2867