i have been given a part which includes a hub . I need to give the dimensions of the hub (with tolerences from the chart attached) being machined to fit in to a ball-bearing using a "tight" fit (the bearing must be "forced" on, but not so much as to make it distort).

secondly i must create another view in which the hub is running in a high percision bronze bushing that is journal bearing.

lastly, i am asked to dimension the bolts that go in to the bolt holes, given that their diameter is 18m.

I know that the tolerences should go by hole basis, so i chose H7/k6 for the first view and H7/g6 for the second, although some chose H7/p6 and H8/f7 for the first and second. Which is more correct?

For the last part should i choose the bolt sizes as 20M (ansi metric) or 16M (ansi metric)?

thank you for your help