When selecting a bearing unit, it is easy to focus first on dimensions, load and speed. However, there is another factor that can significantly influence how well the chosen solution performs in the long term: the operating environment.
There is a considerable difference between a bearing unit operating in a general industrial application and one that is exposed to moisture, frequent cleaning and strict hygiene requirements on a daily basis.
Therefore, when choosing between cast iron, thermoplastic and stainless steel bearing units, the decision should not be based on material alone.
Let’s take a closer look at which design may be the right choice for different operating environments.
Cast Iron Bearing Units – A Reliable Solution for General Industrial Environments
Cast iron bearing units provide a robust and versatile solution for a wide range of general industrial applications.
In NTN-SNR bearing units, the cast iron housing is combined with a pre-lubricated and sealed bearing insert.
Typical applications include conveyor systems, fans, agricultural machinery and various types of manufacturing equipment.
But what about dusty or contaminated environments?
In these conditions, the housing material alone is not enough to consider. Selecting the appropriate sealing solution is also important, as the ingress of external contaminants can affect bearing performance and service life.
If the equipment is regularly exposed to water, moisture or intensive cleaning, it may be worth considering more specialised bearing unit designs.
Thermoplastic Bearing Units – When Hygiene and Cleanability Matter
Think of a food processing or bottling line.
Here, the bearing unit must cope not only with mechanical loads. The equipment may be cleaned regularly and exposed to water and moisture, while hygiene is also a key consideration.
In such environments, thermoplastic bearing units can be an appropriate choice.
In NTN-SNR thermoplastic units, the thermoplastic housing is combined with a stainless steel bearing insert. The bearing inserts feature food-grade seals and are lubricated with an NSF H1-certified lubricant.
The smooth design, which helps reduce the accumulation of contaminants, also supports easier cleaning, making this construction particularly suitable for equipment that is cleaned regularly.
Typical applications include food processing and packaging machinery, bottling equipment, fruit and vegetable processing lines, and conveyor systems that require regular cleaning.
In food industry applications, moisture, high-pressure washdowns, corrosion and production downtime caused by maintenance can all be important factors to consider when selecting a bearing solution.
Stainless Steel Bearing Units – When the Operating Environment Demands More
What happens when moisture and intensive cleaning are not occasional factors, but part of the daily operating process?
In such cases, stainless steel bearing units can become the preferred solution.
Thanks to their corrosion-resistant design, these units can be considered for environments where greater resistance is required than that offered by standard industrial solutions.
Typical applications include meat and poultry processing, intensively cleaned food-industry conveyor systems, and beverage processing equipment.
In NTN food-industry solutions, stainless steel housings are designed with corrosion resistance and regular cleaning – including high-pressure washdowns – in mind.
Typical designations: SUCP, SUCFL, SUCPA, SUCF, SUCT
Important: stainless steel does not automatically mean resistance to everything
The term “stainless steel” does not in itself mean that a bearing unit is compatible with every chemical substance or cleaning process.
If aggressive cleaning agents or other chemicals are used, it is always necessary to check whether the materials of the bearing unit offer sufficient resistance to the specific medium.
In addition to the type of cleaning agent, its concentration and temperature also matter. Therefore, in specialised environments, bearing unit selection should always be based on the actual operating conditions.
Additional Protection with Protective Covers
In certain applications, selecting the appropriate bearing unit may not be enough, and additional protection may be required.
For NTN-SNR thermoplastic units, CV open and CF closed protective covers are available, while stainless steel versions can be fitted with SCO open and SCC closed protective covers.
The appropriate cover can provide additional protection in environments where the bearing unit is exposed to intensive external influences.
Why Consider the Operating Environment from the Start?
The purchase price of a bearing unit is easy to compare.
The total cost of an incorrectly selected bearing unit is much harder to assess.
If a component needs to be replaced prematurely, the cost is not limited to the price of a new bearing unit. Installation time, maintenance resources and – in many operations, even more importantly – the cost of unplanned machine downtime must also be taken into account.
Therefore, over the long term, the lowest purchase price does not necessarily represent the most economical solution.
The goal is to select a bearing unit that is suitable for the specific operating environment.
NTN-SNR and FBJ Bearing Units in Our Range
Our range includes NTN-SNR and FBJ housed bearing units, from designs intended for general industrial applications to solutions developed for wet environments and applications requiring regular cleaning.
When selecting the right bearing unit, however, dimensions should not be the only consideration.
Moisture, contamination, cleaning methods, corrosion risk and hygiene requirements can all influence which design is best suited to a particular machine or application.
Not sure whether you need a cast iron, thermoplastic or stainless steel bearing unit?
Contact us! We can help you select the right solution for your operating conditions.
Frequently Asked Questions About Selecting Bearing Units
Which bearing unit should I choose for a general industrial environment?
For general industrial environments, a cast iron housed bearing unit is usually a good starting point. Thanks to its robust design, it can be used in applications such as conveyor systems, fans, agricultural machinery and various types of manufacturing equipment. In dusty or contaminated environments, it is also important to select an appropriate sealing solution.
When should I choose a thermoplastic bearing unit?
Thermoplastic bearing units are primarily suitable for environments where regular cleaning, moisture and higher hygiene requirements are common. Typical applications include food processing, packaging, bottling and conveyor systems that require regular cleaning.
What is the difference between thermoplastic and stainless steel bearing units?
The main difference is the housing material. A thermoplastic bearing unit combines a plastic housing with a stainless steel bearing insert, while in a stainless steel bearing unit the housing itself is also made of stainless steel. The appropriate solution should always be selected according to the operating environment.
Which bearing units are suitable for food processing machinery?
For food processing machinery exposed to regular washdowns, moisture and hygiene requirements, thermoplastic or stainless steel bearing units may be suitable. NTN-SNR thermoplastic solutions are available with stainless steel bearing inserts, food-grade seals and NSF H1-certified lubricant.
Which bearing units can be used in wet environments that are regularly washed down?
In wet and regularly cleaned environments, thermoplastic or stainless steel bearing units should be considered. When selecting the appropriate solution, factors such as cleaning frequency, corrosion risk and the cleaning agents used should also be taken into account.
Are stainless steel bearing units resistant to all chemicals?
No. Stainless steel construction can provide good corrosion resistance, but this does not mean that it is resistant to every chemical. In addition to the type of cleaning agent or chemical used, its concentration and temperature must also be considered.
Why is proper bearing unit sealing important?
Proper sealing helps prevent dust, water and other contaminants from entering the bearing while also helping to retain lubricant inside the bearing. This is particularly important in dusty, wet or regularly washed-down environments.
What is the purpose of a bearing unit protective cover?
A protective cap or cover can provide additional physical protection for the bearing unit against external contaminants, water or intensive cleaning.
What should I consider when selecting a bearing unit?
In addition to shaft diameter, load and speed, the operating environment should also be considered. Important factors may include moisture, contamination, corrosion risk, the method and frequency of cleaning, and any hygiene requirements.
Where can I find NTN-SNR and FBJ bearing units?
Our range includes NTN-SNR and FBJ bearing units, from standard industrial designs to solutions suitable for wet and regularly cleaned environments. If you are unsure which bearing unit to choose, contact us and we will help you find the right solution for your application.
