What is an Extreme Bearing

SS 316, five times higher load capacity and sealed !

Extreme Bearing housings are made of stainless steel 316 with a double row of rollers and a special seal.

They are a better choice for applications where traditional bearings quickly become worn down by heavy load, rust, soiling, dust, chemicals and the penetration of water.

Extreme Bearings are designed for tough and wet corrosive environments involving heavy loads such as on conveyors, wash drums and graders in potato and seafood processing factories. Thanks to the excellent seals, Extreme Bearings are also very suitable in dry places where there is a lot of dust in combination with heavy bearing loads such as in mining and the extraction of sand on sorting equipment, conveyors and crushers.


Technical features:

  • The housing is made of stainless steel 316,
  • The bearing unit is interchangeable with most known brands of housing and can therefore be used in existing operating machinery.
  • Self-aligning, double row ball bearings to handle high radial and thrust loads.
  •  Particularly suitable in harsh conditions and where aggressive media is used.
  •  SS 316 has a very high resistance to chemicals and sea water.
  •  Standard bearing insert, so a replacement bearing insert can be found anywhere in the world.
  •  IP66: water projected in powerful jets against the enclosure from any direction shall have no harmful effects.
  •  The bearings are very easy to clean. Rounded corners and smooth surfaces both at the front and reverse side do not encourage the build-up of dirt.

Why Extreme Bearing?

All traditional bearing units contain ball-bearing inserts, fitted with a spherical outer ring. The idea is that the bearing is self-aligning. However, this is not always the case. What usually happens is that the force (F) holds the outer ring of the insert firmly in the housing, making it difficult or even impossible to adjust the insert. If the bearings are subject to excessive axial loading, the forces generated penetrate through the bearing, causing damage to the balls, inner ring, ball race and even the housing. Ultimately, the insert has to be replaced, while the bearing housing is also damaged permanently in many cases.

Extreme Bearing takes a different approach.

Extreme Bearing does not use a spherical outer ring, but instead has an (optional) double-row ball bearing or roller bearing. The concave raceway of the outer ring in combination with two rows of balls operate over a wide range of contact angles.  it aligns itself correctly with the shaft and assembly without causing undue stress on the rest of the bearing assembly.

How Extreme Bearings work

Bearing inserts

Double-row ball bearings have the advantage that they are very light and adjustable.

The difference between the ball bearings and the spherical roller bearings in the Extreme Bearing is that the ball bearings are sealed by 2-rs bearing seals while the spherical roller bearings are not. These seals will give extra protection in case the housing’s seals become broken or breached.

Spherical roller bearings have the advantage that they provide a much larger load capacity than ball bearings and can accommodate axial force.

Adapter sleeve

Clever fitting using an adapter sleeve takes away the need for an eccentric clamping ring or allen key, both have been known to cause additional problems. The choice of the used materials contributes to a longer service life and, ultimately, better results and lower costs.

Superior triple sealing

Superior against sand, water and detergents

  1. Double lip centrifugal seal
  2. Grease-filled housing
  3. 2-RS bearing seal

 The Bearing housing is filled with grease to prevent contaminants from entering and damaging the bearing

Standard Extreme Bearing housings feature centrifugal seals, specially developed to repel dirt and contaminants using centrifugal force generated by the shaft.

The gaps between the lips of the centrifugal seal and the stator must be sealed to keep out dust and water. To improve the age of the bearing for centrifugal shaft seals, we used an automatic lubricator.

Many sealing options are possible. Each possesses different properties depending on the application. We would be pleased to advise you to the best choice of seal.

Centrifugal seals and lubrication

Sealing without creating wear on the shaft

Standard Extreme Bearing housings are made of 316 stainless steel. Specially developed centrifugal seals are also used. The rubber of the rotor ring clamps around the shaft and is turning with the shaft vertically against the stator ring. Because the lips are positioned vertically against the stator ring, the dirt will be repelled by the centrifugal force from the sealing lips. The rotor ring can be moved eccentrically in relation to the stator ring. In this way, the centrifugal seal is able to absorb any misalignment of the shaft without creating wear on the rubber lips.

The grease passes the retaining edge through the lubrication channels under the stator ring and between the two sealing lips and stator ring. This makes sure that any dirt is flushed away. The clamping of the rubber rotor ring around the shaft means that the bearing can be assembled even on a shaft which has suffered light surface damage such as a groove.


Berulub FG-H-2-SL is highly recommended as the grease for lubricating Extreme Bearings. It is a high performance and food-safe lubricant.

Due to the low viscosity of the base oil, this grease is very suitable to use in the centrifugal seal. This smooth but tacky grease will make sure that all dirt is kept out of the seal. The high-load capability (four ball weld load >4000N acc. DIN 51 350 P4) makes this grease ideal for all types of Extreme Bearings. We supply the bearings but we do not supply lubricants. For more information about lubricating Extreme Bearings, you are welcome to write to a Dutch distributor of lubricants FenS at the following email address: mmuis@fens.nl.

Axial displacement

Suitable for expansion and contraction of the shaft

The seats are machined to a tolerance to provide a loose fit. The bearing seats in the housings are sufficiently wide to allow axial displacement of the bearing and to accommodate for thermal expansion of the shaft due to high temperatures, such as on a baking conveyor belt.

The Extreme Bearing blocks can absorb expansion of the shaft because there is an adjustment or locating ring in the bearing housing. The locating ring can be removed from a bearing block of a pair placed opposite each other so that axial displacement is possible.