Shoot for a SFNS (slip fit, no slop), ID of bushing to shaft as well as OD of bushing to ID of bearings.
The radial runout shouldn't be an issue as that will be pretty easy to deal with when they OD grind it to size.
The axial runout is what you want to minimize for ball screw work. A person who does reasonable OD grinding should be able to axially "bump" grind the flange when they do the OD grinding work for you. Face runout of the bumped surface should be under a half thou or less....
We do bump grinding of cam sprocket mounting faces all the time when we tune-up grind the faces of billet cams - should take 15-20 mins, half hour tops - to bump the flange, both sides,
I"d figure an hour all totaled assuming the ID was properly reamed for a slip onto the grinding arbor shaft OD.
Although the material would not have to be hardened, a hardened piece of steel would just be more stable.... Flame hardened, quenched and tempered 1050 or so would be more than adequate. Tool steel (IE drill rod)would be overkill....
The above "specs" should do you just fine....  |