2nd flat on 1st end 90 degrees apart from 1st flat
A straight shaft having two or more of the following conditions: a specified surface finish designation in the range of 1 to 125 microinches (o.O25 to 3.2 micrometers), arithmetical average (aa), machined peripheral flat(s), circular groove (s), keyway(s), splines, threads, or holes. It is not designed for use in aligning by fitting into corresponding holes of another item. It may be drilled for lubricating holes. For items having an integral gear(s) or worm(s), see gearshaft (as modified). For items designed to support rotating members see axle(1), straight. For items not having the above conditions see pin, straight, headless. For items having machined ends which constitute steps see shaft(1), shouldered; axle(1), shouldered; and bolt, fluid passage.
Classification: Transmission shafts and cranks, except camshafts and crankshafts
NSN 6685-01-193-7866
NSN 5999-00-826-6509
NSN 2925-00-155-2100
NSN 6135-01-435-8451
NSN
NSN 5935-00-293-1863
NSN 6610-01-317-4859
NSN 5975-01-073-8075
NSN 5935-00-527-8657
NSN 5895-00-596-8678
NSN 5996-01-333-0570
NSN 5895-00-936-3524