A Quick Guide to Mounted Bearings

When selecting a mounted bearing, there are a handful of characteristics that must be taken into consideration in order to maximize its functionality. Two of these characteristics are the housing material and seal-type of the bearing. Depending on the operating conditions, protection requirements, and specific environmental demands, the recommendation for seal-type and housing material varies. Choosing the correct type of bearing for a given situation can sometimes be a bit confusing, but doing so will improve the performance and longevity of the bearing. The following guide can be used to help choose which type of mounted bearing is best for you.


The main job of the seal of a bearing is to maintain lubrication within the bearing while simultaneously protecting it from outside contaminants. For the majority of oil-lubricated bearings, contact seals will be sufficient. Contact seals do a good job of preventing liquids and particles from entering the bearing. However, in more extreme operating conditions, contact seals may overheat and become damaged. When higher performance is anticipated, it is a good idea to consider a labyrinth seal, which is not as prone to overheating and will prolong the life of the bearing. Labyrinth seals also provide a higher level of protection in wet or highly contaminated environments (e.g. dust).

In addition to seals, corrosion-resistant end caps can also often be purchased as upgrades that provide even more protection against moisture build-up. This is especially useful in wet conditions. Two common types of end caps are polymer snap-on end caps, which are easier to install, and stainless-steel bolt-on end caps, which provide additional protection against chemicals. Another benefit of end caps is that they create a safer working environment and help comply with OSHA standards.

Housing Material

Housing material should also be taken into consideration when selecting a mounted bearing, as the type of material used will determine how well it functions under specific operating conditions and environmental demands. In dry environments, a cast iron housing is usually the best option. However, for extra-heavy loads, spheroidal graphite cast will provide more durability and strength. Lastly, in wet environments, stainless steel is generally the preferred material due to its anti-corrosive properties.

No matter what specifications you are looking for in a mounted bearing, the helpful MDS team will be happy to help you get set up with exactly what you need.