High Temperature Bearings: A Complete Guide

High temperature bearings are made to withstand extreme heat and keep working reliably. They help machines run smoothly even in hot conditions.

This blog covers all you need to know about high temperature bearings. Whether you're an engineer, designer, maintenance expert, or buyer, this guide will help you choose the right bearings.

What Are High Temperature Bearings?

High-temperature bearings usually operate in hot environment. They often handle temperatures over 150°C and sometimes as high as 350°C.

Design Features of High Temperature Bearings

Heat-resistant Materials and Stabilization 

High temperature bearings are made from special materials like ceramic, heat-resistant steel, and composites. These materials can handle high heat without losing strength or performance.

The materials used in high temperature bearings will be discussed in detail in a separate section below later.

Enhanced Internal Clearance

Since thermal expansion reduces internal clearance—raising friction and seizure risk—high temperature bearings adopt larger clearances (e.g. C4 or C5) to compensate.

Special Cages and Retainer Materials

In high temperature applications, standard nylon cages may fail. To solve this, special materials like stainless steel or graphite are used instead. These materials can handle more heat and last longer. Graphite can also reduce friction by acting as a solid lubricant.

Seal and Shield Modifications

Many high temperature bearings use metal shields or open designs, as standard seals cannot withstand high temperatures.

If seals are used, high temperature bearings are made from heat-resistant elastomers such as Viton (fluororubber) or silicone rubber.

Note

While fluororubber can withstand high temperatures, it still has its limits. Typically up to 200°C (392°F) for long-term use, and around 250°C (482°F) for short-term exposure.

High Temperature Lubricants or Dry Lubrication

High temperature bearings use special lubricants that can handle extreme heat. Regular bearings use standard grease(up to 120°C), but high temperature lubricants stay effective at much higher temperatures.

The next section will focus specifically on lubrication strategies.

Lubrication Solutions for High Temp Bearings

Standard bearing greases can break down at high temperatures, causing lubrication failure, more wear, and damage to the bearing. To avoid this, high temperature bearings use special lubrication methods, such as:

High Temperature Bearing Greases (up to ~250°C)

• Silicone-based greases
• PFPE-based

Solid Lubricants (Dry Lubrication)

• Graphite - 350°C
• Molybdenum disulfide - 400°C
• Hexagonal Boron Nitride - 1000°C
• Tungsten disulfide - 500°C
• Calcium fluoride - 1300°C

Note

With solid or specialty lubricants, many high temperature bearings are "lubricated for life," eliminating the need for relubrication even under continuous operation.

Table1: Common Brands of High Temperature Grease

Materials of High Temperature Bearings

High-Temperature Steel Alloys

While lubrication plays a key role in high temperature bearing performance, material selection fundamentally defines heat resistance

High temperature steel alloys are mainly used for the balls and raceways of rolling bearings.

Table2: Typical High-Temperature-Resistant Materials

Table3: Materials for Extreme High Temperatures

Table4: Heat Resistance Classification for High Temperature Bearings

Ceramic

Ceramic is often used for high temperature bearing parts like balls, rollers, and rings. It resists heat, doesn’t expand much with temperature changes, and wears down slowly. This makes it a good choice for hot areas where it's hard to use lubrication.

Silicon Nitride (Si₃N₄)

Temperature Resistance: Up to 1,200°C (in non-oxidizing environments).

Key Properties:

• High strength and fracture toughness.
• Low thermal expansion.
• Excellent corrosion and oxidation resistance.
• Self-lubricating properties in some conditions.

Applications:

• Aerospace bearings.
• High-speed machine tool spindles.
• Extreme environment bearings.

Zirconia

Temperature Resistance: Up to 800–1,000°C.

Key Properties:

• High toughness.
• Good wear resistance and low friction.
• Moderate thermal conductivity.

Applications:

• Bearings in moderate high-temperature environments.
• Medical and food-grade bearings (biocompatible).

Silicon Carbide (SiC)

Temperature Resistance: Up to 1,600°C (in inert atmospheres).

Key Properties:

• Extreme hardness and stiffness.
• Superior thermal conductivity .
• Excellent chemical and oxidation resistance.

Applications:

• Bearings in furnaces and nuclear reactors.
• High-load, high-speed applications.

Graphite/Metal Composites

Graphite-Metal Alloy

Graphite-metal alloys are mainly used in sliding bearings and cages. They work well in high-heat areas where self-lubrication is needed to keep things running smoothly without extra grease or oil.

Table5: Common Metal Matrices & Applications

High-Temperature Polymer and Composite Materials

High-temperature polymer and composite materials are mainly used for cages, sliding components, and other non-rolling parts.

It resists high heat and chemical corrosion, and has a low friction coefficient. This makes it ideal for high-temperature applications where smooth, low-friction movement is needed.

Table6: High-Temperature Polymers

Types of High Temperature Bearings 

 High Temperature Ball Bearing

High Temperature Roller Bearing

High Temperature Plain Bearing

High Temperature Pillow Block Bearing

High Temperature Linear Bearing

Applications of High Temperature Bearings

Table7: Industry-Specific Use Cases

Selection Considerations for High Temp Bearings

Temperature Range and Environment

Check how hot your application gets during use. Ceramic bearings can handle up to 1600°C, while high-temp steel bearings work up to about 500°C.

First, determine how hot the application gets and what kind of environment it’s in—air or vacuum. For example, is it 250°C with air flow, or 400°C in a vacuum?

Beyond temperature, other environmental factors such as dust, humidity, and vibration can affect high temperature bearing performance.

Load and Speed Requirements

Bearings need to handle the required loads and speeds at high temperatures. Each bearing type has limits that may drop as temperature rises. Engineers must choose the right high temperature bearings, materials, and lubricants to keep performance and durability steady under these conditions.

Selection depends on load and speed. For high-speed or heavy-load use, rolling bearings (made of steel or hybrid materials) are a suitable choice. For low-speed or extremely hot conditions, self-lubricating bushings are usually a better choice.

Maintenance and Lifespan

High-temperature applications need special bearing lubricants, like high-temp grease or solid lubricants such as graphite or molybdenum disulfide. Using the right lubricant is key to keeping things running smoothly and reducing wear in hot conditions.

Choose the right high temperature bearing based on how often maintenance can be done. If regular lubrication isn’t possible, use ‘’lifetime lubricated’’ options like graphite-lubricated or ceramic bearings. These may cost more upfront but save money over time by reducing downtime and replacements.

Compatibility (Dimensions and Interchange)

Many high temperature bearings come in standard sizes and can directly replace regular ones. If using a different type, ensure it meets design requirements.

Cost vs. Performance Trade-Off

Full ceramic or specialized bearings offer the best heat resistance but are expensive. Balancing cost and performance is important. For example, If a steel bearing handles 200°C, there's no need for a pricier ceramic one rated for 500°C.

Leading Manufacturers and Solutions for High Temperature Bearings

Table8: Leading Manufacturers and Solutions for High Temperature Bearings

Conclusion

High temperature bearings are essential for reliable performance in hot environments. They can withstand heat where regular bearings fail, helping reduce downtime and extending equipment life.

Choosing the right high temperature bearing solution helps prevent failures, lowers maintenance needs, and improves safety in demanding environments.

If you have any questions or specific needs, please contact LILY Bearing.