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HDL Seals

The HDL™ seal features a close-clearance design that contributes to lower torque, operating temperatures and fuel consumption than other lip-type seals.

This close-clearance designed seal never touches the mating surface. Its benefits include lower torque, lower temperatures and better fuel efficiency with fewer set outs, higher service speeds and lower operating costs than other lip-type seals.


Railroad journal roller bearing application

Design Attributes

  • Low torque
  • Low temperatures
  • Better fuel efficiency


Timken’s Hydrodynamic Labyrinth (HDL) seal is one of the key components in the industry-leading packaged rail bearing design. This seal marries the best lip-type and labyrinth (close-clearance) sealing technology.

Compared to conventional lip-type seals, the HDL design:

  • Reduces seal torque and operating temperatures
  • Extends grease life and fatigue life
  • Improves lube film
  • Enhances overall bearing life and performance

Bearings with HDL seals run cooler and keep more grease in the bearing, which keeps dirt, debris and water out.