Seal washers prevent dust intrusion and oil leakage from the threaded portion of bolts.

NOK seal washers prevent not only intrusion by dust or dirt, but also the leakage of oils or other fluids from the threaded portions or flanges of bolts or nipples of various machines, such as hydraulic or water-pressure machines for automobiles, construction machines, and transporting machines.

The seal washers use a specially blended synthetic rubber developed by applying the rubber technique for oil seals. Thus they have superior tear strength, mechanical strength, and resistance to heat, cold, and oils. They also provide stable sealing performance even when they are used for special applications.