This standard establishes flange measurements for a certain number of single row radial or angular contact ball bearings with flanged outer ring. The rest of the main measurements of complete bearings are given in the UNE 18-037 standard. The tolerances for the bearings, except for the flange, are given in the UNE 18-031 standard. This standard will be revised and will include tolerances for the flange. Tolerances for precision bearings for instruments are indicated in the UNE 18-182 standard. The limit measurements of chamfers are indicated in the UNE 18-132 standard.