WHAT IS DOUBLE ROW ANGULAR CONTACT BALL BEARINGS?

Basically double row angular contact ball bearings have three types:

1) with the load lines externally converging.
2) with the load lines externally diverging.

3) with a split inner ring and the load lines externally converging.

Normal Externally Converging Externally Diverging Externally Converging
Split Inner Ring.

The bearings follow the same bore and outside diameter size as the deep groove conrad type bearings in the light, medium and heavy series. However, the width dimension is in inches and two single row A/C bearings together have a larger width dimension than one double row angular contact bearing.

Externally Converging

For externally converging double row A/C bearings we use the ISO numbering systems.

light series  - 3200
medium series  - 3300
heavy series  - 3400
The code for the bore size is the same as deep groove ball bearings.

Seals and shields have the following suffixes:

One Shield  - Z
Two Shield  - ZZ
One Seal  - RS
Two Seals  - 2RS
Snap Ring & Groove  - NR

These bearings have a filling slot on one side of the bearing to allow more balls to be inserted into the bearing and can therefore carry a greater radial load. The slot can clearly be seen in this photograph. Care must be taken to ensure that thrust load is only applied to the side opposite that with filling slot.
For externally converging split inner ring double row A/C bearings we use the same numbering systems above but add the suffix "DA" immediately after the part number.

Externally Diverging

For externally diverging double row A/C bearings we use a "5000" numbering systems. thus:-

Light Series  - 5200
Medium Series  - 5300
Heavy Series  - 5400
Bore codes and sealing suffixes etc. are the same as for the "3000" series.

The standard "externally converging" and the reverse angle "externally diverging" A/C bearings have about equal radial load capacity, in the same size and series, but the standard has slightly more thrust load capacity than the reverse angle.

These series do not have filling slots and can take thrust load from either direction, but with less balls, the radial capacity is reduced. However, beware - some manufacturers do make them with filling slots. Fafnir use "W" suffix on their bearings with filling slot.

Yousen bearings have a hole on the outer ring. This is for assembling the cage during manufacture and not for lubrication as many people think. The hole can be used for lubrication ,

but any standard bearing by any other manufacturer is suitable as a replacement.

When seals or shields are added some manufacturers also increase the width of the bearing. Take care.

Note - Whilst the 3000 series are dimensionally interchangeable with the 5000 series, in almost all cases they do have different capacities and different costs.
If you offer a customer a 5200 series bearing in place of a 3200 series bearing you must advise him that the radial capacity is less. Also when offering a customer a 3200 series bearing in place of a 5200 series bearing you must point out that the bearing has limited thrust capacity in one direction, so care will need to be exercised to ensure that it is fitted the right way.

TAKE CARE WITH INA BRAND BEARINGS AS THEY ONLY MAKE THE 5200 AND 5300 SERIES BUT NUMBER THEM AS 3200 AND 3300 SERIES.