This comprehensive bearing selection guide is designed to assist in choosing bearing materials. From non-corrosive settings to highly corrosive environments with concentrated acids and alkalis, our guide provides concise bearing material recommendations.
In a non-corrosive environment
Here's our guide to choosing bearings tailored to various conditions in non-corrosive settings.
- For normal use at low to moderately high speed and all loads, in temperatures below 120 degrees Celsius (constant) or 150 degrees Celsius (intermittent), we recommend using chrome steel bearings.
- If operating at higher temperatures or speeds, check the grease capabilities. Take our choose your grease quiz if you're unsure.
- Avoid using nylon or polyamide cage bearings at temperatures exceeding 110 degrees Celsius.
For high-speed applications at low to medium temperatures:
- Use chrome steel bearings with high-speed grease. Consider using polyamide cage or ceramic balls for even higher speeds. For higher temperatures, opt for high-temperature grease.
In high-temperature environments (up to 250°C constant or 300°C intermittent):
- Choose 440 stainless steel bearings with a stainless-steel cage. Ensure the grease speed rating matches the operating speed.
For high-speed and high-temperature conditions:
- Use 440 stainless steel bearings with a stainless-steel cage and consider ceramic balls for very high speeds.
For extremely high temperatures (over 300°C):
- Use unlubricated full complement (no cage) all-ceramic bearings. Note that the maximum working temperature for Zirconia (ZRO2) is approximately 600 degrees Celsius and for Silicon Nitride (Si3N4) it is 1200 degrees Celsius.
Moderately corrosive environment
In moderately corrosive environments, the choice of bearings is critical to withstand varying levels of moisture and liquids. Here's a guide to selecting bearings optimised for different conditions in moderately corrosive settings:
- For normal use in low to high speeds, all loads and temperatures below 120°C (constant) or 150°C (intermittent), we recommend corrosion-resistant 440 stainless steel bearings
- In scenarios of low load and speed at temperatures up to 100°C (constant), opt for corrosion-resistant 440 stainless steel bearings. For low precision applications, where rolling accuracy is not important, consider plastic (acetal) corrosion-resistant bearings. Verify load/speed ratings.
- For high-speed applications at low to medium temperatures (below 120°C constant or 150°C intermittent), corrosion-resistant 440 stainless steel bearings are suitable. A polyamide cage and/or ceramic balls will increase maximum speed.
- In high-temperature environments (up to 250°C constant) with very low load/speed, choose corrosion-resistant 440 stainless steel bearings with high-temperature grease or unlubricated plastic PTFE/PEEK bearings. Ensure that you verify load/speed ratings and be mindful of lower rolling accuracy with plastic bearings.
- For high-temperature conditions (up to 250°C constant) with medium to high load/speed, use corrosion-resistant 440 stainless steel bearings with high-temperature grease.
Food environment
In food environments, where bearing location determines lubricant requirements, adhere to USDA regulations by selecting H1 grade lubricants for incidental food contact and H2 grade where there's no contact possibility.
- For normal use with low to high speeds and all loads at temperatures below 120°C constant or 150°C intermittent, employ corrosion-resistant 440 stainless steel bearings with food grease.
- In low load and speed applications at temperatures up to 100°C, choose corrosion-resistant 440 stainless steel bearings with food grease or plastic (acetal) bearings without lubrication, noting potential lower rolling accuracy with plastic bearings and verifying load/speed ratings.
- For high-speed usage at low to medium temperatures, use corrosion-resistant 440 stainless steel bearings with food grease. Consider incorporating a polyamide cage and/or ceramic balls for enhanced performance at higher speeds.
- In high-temperature environments (up to 250°C constant) with very low load/speed, select corrosion-resistant 440 stainless steel bearings with high-temperature food grease or unlubricated plastic PTFE/PEEK bearings, ensuring to check load/speed ratings for plastic bearings.
For high-temperature conditions with medium to high load/speed, use corrosion-resistant 440 stainless steel bearings with high-temperature food grease.
Vacuum environment
In vacuum environments, adapt bearing selection to meet specific operational demands:
- For normal use involving low speed and all loads at temperatures below 120 degrees Celsius constant or 150°C intermittent, use 440 stainless steel bearings with stainless steel cage, either unlubricated, with vacuum grease, or with MOS treatment. Consider hybrid bearings (stainless steel rings & ceramic balls) or all-ceramic bearings.
- In high-speed applications at low to medium temperatures (up to 150°C constant), opt for 440 stainless steel bearings with stainless steel cage, ceramic balls, and vacuum grease.
- In high-temperature environments (up to 250°C constant) with medium to high load/speed, choose 440 stainless steel bearings with stainless steel cage and high-temp vacuum grease. Consider unlubricated all-ceramic bearings for low speeds.
- For very high-temperature conditions (up to 800°C) select unlubricated full complement (no cage) all-ceramic bearings, bearing in mind the maximum working temperature for Zirconia (ZRO2) is approximately 600°C and for Silicon Nitride (Si3N4) it is 1200 degrees Celsius.
If you need further assistance with choosing the correct bearing material, get in touch with our experienced team today by emailing sales@smbbearings.com or fill in the contact form.