A little history...I've made hundreds of similar parts, all the same design with different thread sizes and pitches (both RH and LH) and different "stem" or nose configurations. Never ran into this before. Also seems different supplier had same problem with this part. Personally this seems like...
Fixture is not "threaded rod" it it a precision machined thread with mating "face" for face end of thread to bottom out against. fixture is bored thru and ground for a nice slip fit on a ground "post" about which the whole fixture/part revolves. part mat'l is 4150H, all finishes including...
same size, both arbor and fixture machined with same tooling and gaged with same mics (p.d. and major dia.) yes it is shouldered. Part seems to runout laterally (concentricity) not a perp runout issue.
O.K. here goes, try to bear with me...
Machining a 1.25 x 16 LH internal thread. Using a LH threading bar (right to left), part has been faced, bored and a dia. turned on o.d. in one chucking. Other end of part has 3 bearing dia's (+/- .0003). After part is threaded it is mounted on a threaded...
