Sealing rings that are hard to the workpiece, such as round and square section seals, should be made of rubber with lower hardness. The sealing rings that are soft with the workpiece, such as plate-shaped and flash-shaped sealing rings, can be made of rubber with higher hardness, which can achieve the purpose of being easy to be deformed by the soft flash and the workpiece and ensure the sealing requirements behind the workpiece.

In view of the high hardness rubber waterproof seal ring in the production, we must shorten the time and reduce the temperature, try to reduce its processing hardness, and maintain the essential hardness. If the vulcanization time is too long, the seal ring is particularly brittle and easier to tear. Pay more attention when using it.

The hardness of the sealing ring adjusts the machine and equipment functions of the workpiece. After the workpiece is quenched, the hardness is high and the brittleness is large. In order to meet the different functional requirements of various workpieces, it can be adjusted by fire to adjust the hardness, strength, plasticity and toughness.