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 6320-01-190-1397
NSN 6685-01-240-3752
NSN 6145-00-195-5263
NSN 6645-01-442-6476
NSN 7035-01-029-7221
NSN 5960-01-599-9821
NSN 5985-01-414-5120
NSN 5985-00-967-9264
NSN 6220-01-486-3602
NSN 5935-01-214-8408
NSN 6610-00-906-9451
NSN 5915-00-061-6675