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What is a Rotary Shaftseal?

A rotary shaft seal is a seal used to seal a rotating shaft. This product is made of an elastomer and a metal structure, which allows it to be waterproof and dustproof. Rotary shaft seals are generally used on the following applications: crankshafts, gearboxes, universal joints, camshafts, wheels, etc. They are also used to protect bearings.


What are the different types of rotary shaft seals?

Today, there are many different types of lip seals. Indeed, these seal models are declined depending on the profile, the dimensions as well as the material in order to answer in an optimal way to the various constraints and applications. You will find below the different characteristics of the profiles as well as the different materials.

Profiles :

  • OAS/CC = Double lip with steel springOA = Single lip with steel spring
  • OA/CB = Single lip with steel spring
  • ASP = Double lip reinforced (up to 5 bar pressure)
  • BB = Single lip + single external reinforcement with steel spring
  • BC = Double lip + single outer armature with steel spring
  • DB = Single lip + double outer armature with steel spring
  • DC = Double lip + double outer armature with steel spring
  • BD = Single lip + single external steel reinforcement, without spring
  • CD = Single lip, without spring
  • CK = Double lip, double steel spring

Materials :

  • NBR: also known as NITRILE, this material is mainly used to be in contact with oils and hydrocarbons from -40 °C to +110 °C. This model is also compatible with water and chemicals.
  • FPM: it can also be in contact with oils and hydrocarbons. It is more suitable for high-temperature use, as it can withstand temperatures from -20°C to +200°C.
  • FPMSS: this material indicates that the seal is made of FPM but with a stainless steel spring and not steel.
  • EPDM: it is often used to be in contact with mineral brake fluid and water. In terms of temperature, it can withstand from -50°C to +150°C.
  • MVQ: this material is used for carburation from -80 °C to +175 °C.

How to choose a rotary shaft seal?

First of all, it is important to know that the references on the rotary shaft seals cannot be used effectively to identify them. This is because each manufacturer uses its own part number for these parts. The best way to identify a rotary shaft seal is to measure the assembly: diameter of the shaft, diameter of the housing and thickness of the seal. These dimensions are regularly engraved on the seal. In order to help you, here is an example of a seal reference at 123Roulement :

OAS-35X47X7-NBR :

  • OAS = shape of the rotary shaft seal
  • 35X47X7 = inner diameter X outer diameter X thickness
  • NBR = material used

If not specified, the sealing rings have no direction of rotation (no oil reflux grooves). You can therefore use them without worrying about the direction of rotation.

How to mount your lip seal?

Although it may vary depending on the mounting, the side with the spring is usually mounted on the liquid or viscous side (oil, grease, water, etc.). There is a variant of the rotary shaft seal with a spring on each side, which is known as the "CK" type. It is recommended when the seal must be made between two liquids (oil and oil, water and oil, etc.)

Find your rotary shaft seal on 123Bearing.com

123Bearing is the reference site for the purchase of seals. With a large stock of different product categories and fast delivery, we strive to offer the best possible service to our customers. Are you having difficulties in your search? Do you need precise documentation? Our customer service team is ready to listen to your needs and identify the right rotary shaft seal for your application.