Monton spindle bearings

Monton High Precision Spindle Ball Bearings


Spindle ball bearings are single-row angular contact ball bearings with a contact angle of 15° or 25° that can support load on one side. In respect of their design, their running accuracy and the materials used, they are optimised for highest speed and great bearing capacity.


Monton spindle ball bearings are characterised by the following properties:

Manufacture in grade P4 (or ABEC7) or better

Rings generally made of corrosion-resistant SV30 high-grade steel

Steel or ceramic balls available for all types

Machined solid retainer of fiber-reinforced phenolic resin or special materials, for example for applications involving higher temperatures

15° (C) or 25° (E) contact angle as a standard

Optionally, bearings can be paired with three pre-defined preload classes (L, M, S) or individual preload

Oil or grease lubrication

Open and closed versions available

Assembly, lubrication and packaging pursuant to cleanroom grade 10,000


Open spindle ball bearings


Standard version with large balls for optimum utilization of the bearing interior and solid retainer for high bearing capacity.

The outer ring has one shoulder only. The increased height of the snap feature prevents bearing collapse.

Solid retainer guided on outer ring with low cross-section, particularly well suited for oil injection lubrication.


Closed spindle ball bearings


The non-contact shields do not cause any additional friction torque

The standard shields made of Viton with metal stiffener offer excellent temperature and media resistance

Very narrow sealing gap for high dust protection

Recommended for grease lubrication, increases the longer service life

Same outer dimensions as open spindle bearings

This design requires often smaller balls, resulting in a lower bearing capacity but higher axial stiffness and speed limit (usually signified by an index letter after the basic type in the part number).

Also available without closure as high-speed version


Handling evidence:


Leave the bearing in its air-tight package until you are ready to start the assembly.

Ensure extreme cleanliness at the workplace.

Avoid shocks and impacts.

Axial load must only act on spindle bearings as indicated by the <s></s>marks on the outer ring.

Use suitable assembly tools to ensure that no assembly forces can be transferred through the balls.

Duplex bearings of pairing types -1 (DB), -2 (DF), -3 (DT) are always packed in pairs and can only be assembled in the specified arrangement with the other bearing in the package.

Universally matched bearings can be freely paired with each other, i.e. you may combine bearings from different packages or lots. These bearings may be assembled in any arrangement.

Before start of operation, allow the bearing to run in at high speed.

Angular contact spindle bearings

These articles are angular contact ball bearings with extremely restricted tolerances. They are particularly suitable for support systems which require the maximum guiding precision and the capacity to reach high rotational speeds. These bearings are mainly used to support machine tool spindles.


Spindle bearings with low friction coefficient

The cages are normally made of plastic material (phenolic resin, peek, polyamide etc.). Thanks to utilize of these materials is possible to have spindle bearings with a low friction coefficient, very light and hence particularly suited to high speeds.


Spindle bearings are a specific version of the single-row angular contact ball bearings They are specifically used in machine tool construction, but also in other fields where high up to highest requirements must be met in terms of precision and/or the admissible speed.

Spindle bearings differ from the standard angular contact ball bearings by the contact angle, the tolerance classes and the cage design. Spindle bearings are available with a contact angle of 15° and/or 25°.

Spindle bearings come in series B719, B70, B72 and A73. Combinations such as HCB70 and HCB719 are available on request.

The spindle bearings are supplied in universal design as standard. The types of universal designs and arrangement of the bearings are described in section Single-row angular contact ball bearings.



The standard cage of spindle bearings is a window cage with guide flange of hard fabric. The cage can be used for longer periods at temperatures of up to 100 °C.



Spindle bearings are typically built in tolerance class P4S. Tolerance classes P4, P2, P2S or HG are available on request.

The dimensional tolerances of bores and outer diameter of spindle bearings are covered by up to three ranges.

The mean dimension of the ranges is indicated as actual value parameter in µm at the outer ring

(e.g. <-3>) and/or inner ring (e.g. <-1>).

In addition, the actual deviation from the nominal dimension of the bearing width is indicated in µm at the outer ring (e.g. <-3/-70>).

The label of the package shows the actual value parameters without deviation of the bearing width (e.g. *-1/-3*).


Heat treatment

Spindle ball bearings have been heat treated so that they can be used up to an operating temperature of 150 °C and in bearings with an outer diameter over 240 mm up to 200 °C while maintaining the accurate dimensions. For temperatures above 100 °C a different cage material should be selected, e.g. brass.


Sealed spindle bearings

The bearings are provided with sealing gaskets which do not contact the inner ring guide flange diameter at both sides (suffix .2RSD).

The sealed version of the standard spindle ball bearing is greased by the grease Klüberspeed

BF 72-22 of the manufacturer Klüber, alternatively by grease Turmogrease Highspeed L252 of the manufacturer Lubcon.