As the name suggests, corrosion-resistant bearings can be used in applications where corrodible materials wouldn’t suffice — think food processing, chemical manufacturing, pharmaceutical production and bearings for marine applications.
Stainless steel is the most obvious choice for corrosion resistance. SMB Bearings supplies 316 stainless steel marine grade bearings with polyethylene, PEEK or PTFE cages. All these cages provide corrosion resistance to water, salt water and most chemicals.
As an alternative to 316 stainless steel, the more common 440 grade stainless steel bearings have good resistance in damp environments and are often used in the food and beverage industry where bearings are frequently washed down. Unlike 316 stainless steel, they have poor resistance to salt water and many stronger chemicals such as caustic cleaning fluids.
That said, it’s not just stainless steel that offers corrosion resistance.
Full ceramic bearings, made from zirconia or silicon nitride with PEEK cages and seals are not affected by sea water and can therefore be used in marine environments, even when fully submerged. Similarly, plastic bearings, with 316 stainless steel or glass balls, have very good resistance to corrosion. These are often made from acetal resin (POM) but other materials are available for stronger acids and alkalis such as PEEK, PTFE and PVDF. These plastics also have good resistance to chlorine and are often used in swimming pool equipment. However, these should only be used in low load and low precision applications.
For advice on the correct bearing material for your application, call the SMB Bearings team on +44 (0) 1993 842 555.