5. Process according to
claim 1 wherein at least one support rail (
15) that is concentric to the centering devices (
11) is ground by means of an intermediate region (
29) having an enlarged diameter lying in between the end regions (
28) of the shaft part (
9) so as to decrease the gap (
8) between the grinding wheel (
1) and the regulating wheel (
2) in this intermediate region (
29).