Ball bearings are available with different types of shields and seals. Bearing closure can extend the bearing life by preventing contaminants from reaching the critical surface inside the bearing.
ZZ: pressed steel shield
non-removable
non-contact
no increased torque
shields material on stainless steel bearings are AISI 300 sereis stainless steel
Z means single shield.
2RS: contact rubber seals
removable
greatly increased torque
greatly reduce lubricant leakage
reduce the max. speed of a bearing
RS means single seal.
2RU: non-contact rubber seals
removable
no increased torque
high speed
ZZS: steel shield with snap ring
removable
non-contact
no increased torque
shields material on stainless steel bearings are AISI 300 sereis stainless steel
TTS: teflon seal with snap ring
removable
increased torque
reduce the max. speed of a bearing
excellent chemical resistance