bearings and ballscrew dont fit each other

[ptjw7uk]

Thats strange 6000zz should be 10.00 mm bore and the 6001zz should be 12.00 bore.
I suggest you just emery the ends of the screw or try new bearings.
Never found bearings to be that undersize.

Peter

[Jonathan]

There is definitely an error in the way you're measuring the bearing bores as the tolerances on bearing dimensions is very tight - a few micrometers at this size.
More worryingly, why are you using deep groove (6000 series) bearings on a ballscrew, not angular contact bearings? If you get the bearings you have to fit they will probably only last a few months since they're not designed to tolerate axial loads. Angular contact bearings are, so you need to get a pair of 7200 and 7201 bearings and the appropriate mount for them, or double row bearings may be acceptable (5200, 5201).

[Gary]

It is more likely the verniers are not accurate.

Thats strange 6000zz should be 10.00 mm bore and the 6001zz should be 12.00 bore.
I suggest you just emery the ends of the screw or try new bearings.
Never found bearings to be that undersize.

Peter