SKF double row deep groove ball bearings

In 4200 ATN9, the first two digits are the series and the last two the bore size, read as in other bearings: 4201 ATN9 and 4204 ATN9 are the sizes that follow. The final letters are part of the designation across the whole catalog line and are copied in full.

The series is recognized by the initial 4. It should not be confused with other double row families: angular contact bearings start with 3 and self-aligning ball bearings with 1 or 2. They have similar dimensions and different functions, and each has its own page. A series 42 bearing shares bore and outside diameter with the series 62 bearing of the same size, but is wider.

With two rows of balls in deep raceways, this bearing is stiff against tilting. It does not align itself: if the shaft deflects or the seats are not in line, one of the rows carries more and the bearing has a short life. For shafts that are not aligned, a self-aligning ball bearing applies.

Nor is it the right choice when the axial load is the main one. For that there is the double row angular contact bearing, which takes thrust better because of its inclined raceways. The double row deep groove bearing is for mostly radial load, with some axial, in a well-aligned arrangement.

Send us the complete designation and the quantity. If it cannot be read, measure bore, outside diameter and width: the width is what tells it apart from a single row bearing. Tell us which machine it runs on and whether the removed bearing had both rows visible or was capped. A photo from the side is enough to confirm the family.