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Shield & Seal Types

Seals and shields are protective closures that retain lubricants and assist in preventing contaminants from reaching internal surfaces. When specifying a seal or shield, consideration should be given to the compatibility of the cage and enclosure type to allow for appropriate clearance. In torque-sensitive applications, it may be advantageous to use shields rather than seals because there are no contacting surfaces to create drag.

The following includes the common types of shields and seals offered by NHBB. Please consult the factory for help in determining the appropriate seal or shield for your particular application.

Seal and Shield Types

Removable with snap wire
Minimal clearance
Most popular
Z Stainless steel 300 series 600 °F
Seal with snap wire
Provides minimal clearance to light contact resulting in low torque
L Glass-reinforced PTFE 400 °F
L seal with backing plate
Excellent sealing characteristics
LBP Glass-reinforced PTFE seal, metallic backing plate 400 °F
Excellent sealing characteristics
D Buna-N bonded to steel insert 250 °F
Excellent sealing characteristics
High cost
D1 Viton® bonded to steel insert 400 °F
Seal, lip riding
Excellent sealing characteristics
Q Glass-reinforced PTFE 400 °F
Seal with protective shield, lip riding
Excellent sealing characteristics
Q4 Glass-reinforced PTFE 400 °F

* Rings and balls are heat stabilized to 300 °F.
Viton® is a registered trademark of DuPont.