Shielded Vs Sealed Bearing: How to Choose?

Choosing between shielded and sealed bearings is not always easy, especially if you do not understand their key differences.

To help you make a quick decision, I will explain what shielded bearings and sealed bearings are, how they work, and the main differences between them based on my 10 years of bearing experience. After reading this article, you will have a clearer idea of which type is more suitable for your application.

If you still cannot decide after reading, or if you need to buy shielded or sealed bearings, you can contact BKZ Industry. As a bearing manufacturer with 15 years of manufacturing experience and 2 factories, BKZ Industry can help you confirm the suitable bearing type and provide reliable supply.

Part 1. Key Difference Between Sealed and Shielded Bearings: Table Comparison

To save your time, you can first check the table below for a quick overview of the main differences between sealed bearings and shielded bearings.

From this comparison, you can see that the key difference is the protection level and running performance.

Sealed bearings are more suitable for applications where dust, dirt, moisture, or water may enter the bearing. They can also keep grease inside the bearing better.

Shielded bearings are more suitable for applications that require higher speed, lower friction, and lower cost. However, their protection against moisture and fine contamination is not as strong as sealed bearings.

If you are still not clear about the difference and do not know how to choose, keep reading. We will explain sealed bearings and shielded bearings step by step.

Part 2. Sealed Bearing vs Shielded Bearing: What Are They?

First of all, let’s check what sealed bearings and shielded bearings are.

What Are Sealed Bearings?

Sealed bearings are bearings with rubber or synthetic seals on one side or both sides. The most common type is the rubber sealed bearing.

In the bearing number, sealed bearings usually come with RS or 2RS. RS means the bearing has one rubber seal on one side. 2RS means the bearing has rubber seals on both sides.

For example, 6202-2RS means a 6202 bearing with rubber seals on both sides.

Watch this video to check the sealed bearing:

What Are Shielded Bearings?

Shielded bearings are bearings with metal shields on one side or both sides. Some people also call them metal shield bearings.

In the bearing number, shielded bearings usually come with Z, ZZ, or 2Z. Z means the bearing has one metal shield on one side. ZZ or 2Z means the bearing has metal shields on both sides.

For example, 6202-ZZ means a 6202 bearing with metal shields on both sides.

Watch this video to check the shielded bearing:

Although sealed bearings and shielded bearings use different covering materials, they have a similar basic purpose: to help protect the bearing from contamination and help keep lubricant inside the bearing.

The difference is that sealed bearings usually offer better protection against dust, dirt, moisture, and grease leakage, while shielded bearings offer lower friction and better speed performance, but their protection level is more limited.

Part 3. Shielded vs Sealed Bearings: Structure

Sealed bearings have both contact seal and non-contact seal options.

Contact seals touch the inner ring or sealing groove, so they provide better protection against dust, dirt, moisture, and grease leakage. However, they also create more friction and may reduce the bearing speed.

Non-contact seals do not directly touch the inner ring, so they create less friction and can support higher speed than contact seals. But their sealing performance is usually not as strong as contact seals.

Shielded bearings do not have direct contact with the inner ring. There is usually a small gap between the metal shield and the inner ring. Because of this non-contact structure, shielded bearings generate less friction and can run at higher speeds. However, their protection level is lower than sealed bearings.

Part 4. Shielded vs Sealed Bearing Pros and Cons

Sealed Bearings

Pros:

• Good protection against dust, dirt, moisture, and light contamination.
• Better at keeping grease inside the bearing, so grease leakage is reduced.
• More suitable for dirty, dusty, or humid working environments.
• Usually requires less maintenance because the lubricant is better protected.

Cons:

• Contact sealed bearings generate more friction than shielded bearings.
• The running speed is usually lower than shielded bearings.
• Heat generation may be higher in high-speed applications.
• The cost is usually higher than shielded bearings.

Shielded Bearings

Pros:

• Generate less friction because the metal shield does not contact the inner ring.
• Usually support higher running speed than sealed bearings.
• Can protect the bearing from larger particles and some external contamination.
• The cost is usually lower than sealed bearings.

Cons:

• Less effective at protecting the bearing from fine dust, dirt, moisture, and water.
• Grease retention is weaker, so grease leakage may be more possible.
• Not suitable for wet, humid, or heavily contaminated environments.
• May require more attention if the working environment is dirty.

Part 5. What Is Better, Sealed or Shielded Bearings?

So, which one is better: sealed bearings or shielded bearings?

In general, it is not correct to say one is always better than the other. They are designed for different working conditions, and both have their own advantages.

The better option depends on your application, speed, working environment, maintenance requirements, and budget.

Part 6. How to Select Sealed or Shielded Bearings?

So, how should you select between sealed and shielded bearings?

If the bearing needs to work in an environment exposed to dust, dirt, moisture, water, or light chemical contamination, sealed bearings are usually the better option. They can offer better protection and help keep the grease inside the bearing, so they are also better for applications that require less maintenance.

For example, in mining machinery, agricultural equipment, outdoor equipment, and marine working conditions, sealed bearings are often more suitable.

If the bearing needs to run at higher speed with lower friction and lower cost, and the working environment is relatively clean, shielded bearings may be the better option.

For example, shielded bearings are commonly used in electric motors, fans, blowers, and some automotive applications where the bearing is not directly exposed to heavy dust, water, or moisture.

If you cannot make the final decision, you can send your bearing number and working conditions to BKZ Industry. BKZ Industry will help you confirm whether sealed or shielded bearings are more suitable and provide the right quotation for your application.

Part 7. FAQS About Sealed and Shielded Bearing

Final Words

Now, with this article, you can understand the difference between sealed and shielded bearings and know how to select the right type for your application. If you need to buy sealed or shielded bearings, you can contact BKZ Industry. With 2 factories, BKZ Industry can manufacture the sealed or shielded bearings you need.