Corteco is an aftermarket specialist within the Freudenberg Group, providing sealing solutions backed by the engineering and manufacturing expertise of Freudenberg Sealing Technologies.

The brand is particularly associated with radial shaft seals, Simmerring® products, valve stem seals, engine gaskets and other sealing solutions for passenger cars, commercial vehicles and Heavy Duty applications.

What makes Corteco particularly relevant in the replacement-parts market is its direct connection to Freudenberg - a company with almost a century of experience in developing sealing technologies for automotive and industrial applications.

For professional buyers, workshops and technical specialists, Corteco therefore represents more than simply another aftermarket brand. It provides access to replacement components supported by the sealing expertise and OE background of the Freudenberg Group.

What Is the Connection Between Corteco and Freudenberg?

Corteco is part of the Freudenberg Group and specialises in the independent automotive aftermarket.

Freudenberg Sealing Technologies is one of the major Freudenberg business groups responsible for developing advanced sealing technologies for automotive and industrial applications.

This relationship gives Corteco direct access to technological expertise developed within the Freudenberg organisation.

Corteco describes its role as bringing Freudenberg's original equipment expertise to the independent aftermarket.

For customers, this connection is important because it links replacement parts with a company deeply involved in the development and manufacture of original equipment sealing solutions.

From Early Seals to the Simmerring®

The history behind Corteco's sealing technology goes back much further than the Corteco brand itself.

In 1929, Freudenberg began producing its first sealing products.

An important breakthrough followed in 1932, when Freudenberg developed the Simmerring® radial shaft seal.

The name Simmerring® is associated with Walther Simmer, a Freudenberg engineer involved in its development.

The new sealing concept helped replace earlier felt-based solutions and became an important milestone in the development of modern radial shaft sealing technology.

Today, Simmerring® remains one of the best-known sealing technologies associated with Freudenberg Sealing Technologies.

What Is a Corteco Simmerring®?

A Simmerring® is a radial shaft seal designed for applications where a rotating shaft passes through a stationary housing.

Its primary functions can include:

• retaining oil or lubricant inside the assembly
• reducing leakage along the rotating shaft
• limiting the entry of external contaminants
• protecting internal mechanical components

In automotive applications, radial shaft seals can be found around crankshafts, camshafts, transmissions, differentials and other rotating components.

The exact design depends on the application.

Corteco Radial Shaft Seals

Radial shaft seals are one of the most important sealing product groups within the Corteco range.

They operate at the interface between a rotating shaft and a stationary housing, where the sealing lip maintains controlled contact with the shaft surface.

Depending on the specific Corteco reference, radial shaft seals may differ in:

• dimensions
• sealing material
• lip geometry
• number of lips
• outside diameter construction
• sealing direction
• application
• installation requirements

For this reason, a Corteco oil seal should not be selected solely because another seal has the same three nominal dimensions.

Corteco Offers Thousands of Sealing References

Corteco's official sealing portfolio includes more than 6,500 different shaft seals, Simmerring® products and valve stem seals, as well as more than 7,000 gaskets.

This broad coverage is particularly important in the automotive aftermarket, where thousands of different engines, transmissions and vehicle applications need to be supported.

The range also demonstrates an important advantage of dealing with a specialist sealing brand: customers can search not only for a generic seal size but for an application-specific replacement reference.

Corteco Valve Stem Seals

Valve stem seals are another important part of the Corteco sealing portfolio.

Their function is different from that of a conventional radial shaft seal.

A valve stem seal controls the amount of oil reaching the valve guide and valve stem area.

The objective is to provide sufficient lubrication while limiting excessive oil from entering the combustion chamber.

Correct oil metering in this area can influence:

• oil consumption
• emissions
• valve guide lubrication
• engine operation
• long-term component performance

Valve stem seals are therefore small components performing a highly specific function inside an engine.

Corteco Engine Gaskets

Corteco also supplies a broad range of engine and automotive gaskets.

Unlike radial shaft seals, which operate against rotating components, gaskets are generally used to seal stationary interfaces between assembled parts.

Depending on their application, they may need to seal:

• engine oil
• coolant
• gases
• air
• other automotive fluids

The material and construction must therefore correspond to the temperature, medium, pressure and mechanical conditions at the specific sealing location.

Corteco Heavy Duty Solutions

The Corteco range also extends into Heavy Duty applications.

These products support vehicles and equipment operating under demanding conditions, including commercial and heavy vehicle applications.

Heavy Duty sealing requirements may involve:

• long operating periods
• contamination
• temperature variations
• high mechanical loads
• demanding maintenance intervals

Correct product identification is particularly important in such applications because seal dimensions alone may not provide enough information to determine interchangeability.

Why Are Radial Shaft Seals So Important?

A radial shaft seal is often inexpensive compared with the mechanical assembly it protects.

Its failure, however, can have much greater consequences.

Oil leakage may contribute to:

• lubricant loss
• inadequate lubrication
• contamination of surrounding components
• premature component wear
• additional workshop labour
• machine or vehicle downtime

This is why the purchase price of an oil seal should not be considered independently of the cost of accessing and repairing the assembly.

If replacing a seal requires significant disassembly, avoiding premature repeat repair becomes particularly important.

What Does OEM Quality Mean for Corteco?

Corteco positions its product portfolio as OEM quality.

This reflects the brand's relationship with the Freudenberg Group and access to expertise associated with original equipment development and production.

This distinction is valuable in the aftermarket.

A replacement component may look simple, but its performance depends on details such as:

material formulation, lip geometry, contact conditions, dimensional accuracy and application-specific design.

The technological background behind a sealing product can therefore be as important as the dimensions printed on it.

What Materials Are Used in Radial Shaft Seals?

The correct sealing material depends on the application.

Common material families found in radial shaft sealing technology include:

NBR - widely used for many applications involving mineral oils and lubricating greases.

FKM / FPM - used where different temperature and chemical resistance properties are required.

PTFE - used in specialised sealing designs requiring properties such as low friction, chemical resistance or operation under conditions beyond those suitable for some conventional elastomers.

Other materials and compound technologies are also used according to the specific seal and application.

A material should never be selected solely because it is considered more expensive or technically advanced.

The correct material is the material that matches the actual operating conditions.

Why Can an Oil Seal Fail Prematurely?

Not every seal failure is caused by a defective seal.

Common causes of premature leakage include:

• incorrect seal selection
• incompatible sealing material
• incorrect dimensions
• installation damage
• damaged sealing lip
• incorrect installation direction
• worn shaft surface
• corrosion on the shaft
• scratches in the sealing area
• contamination during installation
• excessive or unsuitable operating conditions

When the same seal position repeatedly develops a leak, replacing the seal again without identifying the underlying cause may not solve the problem.

Why Does Shaft Condition Matter?

The sealing lip runs directly against the shaft.

This makes the condition of the shaft surface critical.

A shaft can develop a visible wear groove exactly where the old sealing lip operated.

Installing a new Corteco seal onto the same damaged running surface may result in another leak even when the replacement seal itself is completely correct.

Before installation, the shaft should therefore be inspected for:

• wear grooves
• corrosion
• scratches
• sharp edges
• mechanical damage
• contamination

The housing bore should also be checked before installing the replacement.

How to Select the Correct Corteco Oil Seal

Where available, identification using the complete Corteco reference or OE number is generally preferable.

For dimensional and technical identification, check at least:

1. Shaft diameter
2. Outside diameter / housing bore
3. Seal width
4. Material
5. Lip design
6. Operating medium
7. Operating temperature
8. Shaft speed
9. Corteco or OE reference
10. Application

For example, two radial shaft seals may both have dimensions:

35x52x7 mm

but this does not automatically mean they are interchangeable.

Their materials, lip designs or intended applications may be different.

How to Install a Corteco Radial Shaft Seal

Correct installation can have a direct influence on seal life.

Before installation, the shaft, housing and seal area should be clean and inspected for damage.

The sealing lip should not be dragged across sharp shaft edges, threads or splines without suitable protection.

The seal should also be installed evenly.

Driving one side significantly deeper than the other can damage the seal or result in incorrect positioning.

Where a specific Corteco or Freudenberg product requires a dedicated installation procedure, the manufacturer's instructions should take priority over general installation practices.

Is Every Corteco Seal a Simmerring®?

No.

Corteco has a much broader product portfolio.

Depending on the market and application, the range includes products such as:

• Simmerring® radial shaft seals
• other shaft sealing solutions
• valve stem seals
• engine gaskets
• sealing kits
• vibration control components
• suspension and steering components
• cabin air filters
• other automotive aftermarket components

Simmerring® technology is an important part of Corteco's sealing heritage, but it does not represent the entire Corteco product range.

Corteco vs Freudenberg Sealing Technologies - What Is the Difference?

This distinction is useful for buyers researching the brand.

Freudenberg Sealing Technologies develops and manufactures sealing technologies for original equipment and industrial markets.

Corteco specialises in bringing products and expertise from the Freudenberg Group to the independent automotive aftermarket.

They are therefore closely connected, but they do not serve exactly the same market function.

This relationship explains why Corteco is strongly associated with OE sealing technology despite being an aftermarket brand.

Why Professional Buyers Choose Application-Specific Seals

For professional buyers, purchasing a shaft seal based only on dimensions can create unnecessary risk.

A more complete identification process considers:

reference + dimensions + material + construction + application.

This becomes particularly important for:

• automotive workshops
• engine rebuilders
• gearbox repair companies
• maintenance departments
• technical distributors
• professional parts buyers

Correct identification at the purchasing stage can help avoid installation of an unsuitable seal and the cost of repeating the repair.

Corteco at simmering.pl

simmering.pl offers a broad selection of Corteco radial shaft seals and other sealing products for professional and individual customers.

Products can be identified using information such as:

• Corteco reference
• seal dimensions
• material
• application
• existing seal markings

The Corteco range at simmering.pl is relevant to:

• automotive workshops
• service companies
• technical repair businesses
• maintenance departments
• professional B2B buyers
• individual customers

Our warehouse and store are located in Lublin, Poland, while orders are supplied throughout Poland and to international customers.

FAQ - Corteco, Freudenberg and Simmerring®

What is Corteco?

Corteco is an independent automotive aftermarket specialist within the Freudenberg Group, offering sealing and other automotive replacement solutions.

Is Corteco part of Freudenberg?

Yes. Corteco belongs to the Freudenberg Group.

What is the relationship between Corteco and Freudenberg Sealing Technologies?

Corteco provides aftermarket access to products and sealing expertise originating from the Freudenberg Group and Freudenberg Sealing Technologies.

What is a Simmerring®?

Simmerring® is a radial shaft sealing technology associated with Freudenberg Sealing Technologies and used for sealing rotating shafts.

When was the Simmerring® developed?

Freudenberg developed the Simmerring® in 1932. The company had begun producing early sealing products in 1929.

Where does the name Simmerring come from?

The name is associated with Freudenberg engineer Walther Simmer.

Does Corteco only sell oil seals?

No. Corteco's portfolio also includes valve stem seals, gaskets, vibration control components, filters and other automotive aftermarket products.

How many sealing products does Corteco offer?

Corteco states that its portfolio includes more than 6,500 shaft seals, Simmerring® products and valve stem seals, as well as more than 7,000 gaskets.

Are Corteco products OEM quality?

Corteco officially positions its products as OEM quality, drawing on the OE expertise available within the Freudenberg Group.

Can two Corteco oil seals with the same dimensions be different?

Yes. Identical nominal dimensions do not necessarily mean identical material, lip design or application.

Where can I buy Corteco oil seals?

simmering.pl offers Corteco radial shaft seals and other technical sealing products for individual, professional and B2B customers.

Corteco - Aftermarket Access to Freudenberg Sealing Expertise

The value of Corteco is not based simply on the number of part numbers in its catalogue.

Its key distinction is the connection with Freudenberg and Freudenberg Sealing Technologies.

From Freudenberg's early sealing developments in 1929 and the introduction of the Simmerring® in 1932, sealing technology has evolved through new materials, lip designs, manufacturing processes and application-specific solutions.

Corteco brings this technological background to the independent aftermarket.

For workshops, technical buyers and professional users, this provides an important combination:

aftermarket availability + broad application coverage + OEM quality + Freudenberg sealing expertise.

simmering.pl provides access to a broad selection of Corteco sealing products for customers looking for professional radial shaft seals and replacement sealing solutions.