how to make a ball bearing today?

Answer 1

Ball bearings are made by dropping molten metal into a salt quench bath. The resulting balls are sized accordingly, the ones too far out of specifications are then put back for remelt.

Then they enter a 5 step heat treatment process after which the finishing steps below are taken

Then the approximate sized ones are centerless ground and polished ground to an extremelty high finish and close tolerances using a computer controlled optical methods for measurements.and to control the grinding and polishing. .