C3 bearing / ZZ bearing / 2RS bearing / bearing codes
What do C3, ZZ and 2RS mean in bearing codes?
A practical explanation of bearing clearance, shields and seals for catalog and product code interpretation.
C3 is an internal clearance mark
C3 indicates greater radial internal clearance than normal. It can be suitable where heat, tight fits or expansion reduce clearance during operation.
ZZ indicates metal shields
ZZ usually means metal shields on both sides. It gives basic protection against dust but is not the same as a contact seal.
2RS indicates contact seals
2RS usually means rubber contact seals on both sides. It can improve contamination protection, while friction and speed limits must still be checked.
FAQ
Is C3 always better?
No. C3 is correct only when the application requires additional internal clearance.
What is the basic difference between ZZ and 2RS?
ZZ uses metal shields; 2RS uses rubber contact seals for stronger contamination protection.