An insert is a deep groove ball bearing sealed on both sides that is installed in a housing to form a bearing unit or housing unit. The material used is steel or stainless steel. The bearing is mounted on the shaft by means of set-screw lockings, adapter sleeve lockings  or eccentric collar lockings. The corresponding bearing housing is available in various designs, e.g. as a pillow block or flange bearing, and in various materials.


The insert has a spherical outer ring. Matching to this, the seat in the housing is hollow spherical. AtASK, the ball bearing sits firmly in the housing and can be tilted with great force. Misalignments can be compensated within certain limits. AtASAHI, the ball bearing sits somewhat looser. Here, too, misalignments can be compensated for within certain limits. Both brands have an anti-rotation device that holds the insert bearing in the housing.

Application areas

Together with the housing, the bearing forms the housing unit. The range of application is determined by the bearing unit, not by the insert. Only the type of mounting on the shaft is determined by the insert . Bearing units are used to support shafts.

Technical basics of inserts

The technical basics apply to all kinds of bearing units. The topics of lubrication, sealing, fits, tolerances etc. are stored in the knowledge base under bearing units. Further information is also available in the maintenance and operating instructions and under FAQ.

Types of inserts

Inserts (ball bearings) are manufactured in three different designs. On the one hand, they differ in the way they are mounted on the shaft. There are three different types of mounting:


With set-screw locking:

With eccentric collar locking:

With adapter sleeve locking:

Mounting on the shaft

The inserts are available in three different versions for mounting on the shaft. The standard version is the one with grub screws, which are used as locking screws. The mounting with an adapter sleeve or with an eccentric locking collar is chosen if one does not want to have any imprints of the locking screw on the shaft. The size of the bearing unit to be used is determined by the shaft diameter.



Insert differ in material, internal design and mounting on the shaft. The inserts of series 200 are the standard and correspond in many dimensions to deep groove ball bearings of series 62. Inserts of series 300 are for high loads and correspond more to deep groove ball bearings of series 63. Inserts of series 000 can be used for low loads.



Outer rings, inner rings and steel balls are made ball bearing steel.
Standard version :         JIS SUJ2 (DIN 100CR6)
Stainless steel version:  JIS SUC440C (DIN X105CrMo17).



The deep groove ball bearings are sealed with an oil- and heat-resistant rubber seal. Outer flinger rings made of pressed steel on the UC and UK bearings are attached to the inner ring of the bearing and thus effectively prevent the ingress of dirt. The pressed steel reinforced rubber seal is attached to the outer ring of the bearing and rubs on the inner ring. The combination of these two sealing elements keeps dirt and moisture out from the outside, retains the grease in the bearing and thus ensures perfect running. For operation in difficult conditions such as mills, foundries, etc., the housing units can be fitted with additional covers as special equipment.



Our bearing units are filled ex works with a standard grease for rolling bearings. Should grease leak out during commissioning, it should be removed. Relubrication must be carried out with a suitable grease gun.


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Bearing Units