07-13-2013, 08:08 PM
That sounds correct except for the "the threading exit diameter .2983" which is .3125 (the minor diameter for that thread size) but I don't think that will matter much if you're just looking for clearance where the thread ends. You might want to practice on some thick walled conduit you can get cheap at any home center. Look for the grey colored PVC conduit. It's cheap and you won't likely damage your lathe or yourself while you practice.
Good luck.
Ed
Good luck.
Ed