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Radial Shaft Seals
Seal Performance You Can Trust – Simmerring® Radial Shaft Seals
When it comes to protecting your machinery, every detail matters. Radial shaft seals—often called oil seals or rotary lip seals—are the unsung heroes that keep your systems running smoothly. They prevent costly lubricant leaks, block harmful contaminants, and safeguard the integrity of your rotating assemblies.
At the heart of this technology is Simmerring®, a name synonymous with innovation and reliability. Engineered through decades of expertise, Simmerring seals power millions of applications worldwide—from gearboxes and pumps to electric motors and industrial equipment.
Why choose Simmerring®?
- Precision Engineering: Each seal features a finely tuned lip and a spring-loaded design for consistent pressure and superior sealing performance.
- Extended Equipment Life: Reduce friction, heat, and oil degradation—boosting efficiency and lowering maintenance costs.
- Proven Durability: Built to perform in demanding conditions, including high-speed and high-temperature environments. The right seal doesn’t just protect—it transforms your system’s reliability and reduces total cost of ownership. When performance matters, trust the original: Simmerring® radial shaft seals.
Material Expertise That Drives Performance
Radial shaft seals are crafted from advanced proprietary materials that provide outstanding thermal resistance, robust wear durability, and minimal friction. Developed through extensive research and rigorous dynamic testing, these materials are designed to ensure compatibility with a wide variety of lubricants, shaft surfaces, and challenging operating conditions.
Whether it’s high-speed rotation, aggressive media, or extreme temperatures, our materials are formulated to meet the demands of modern powertrain and industrial applications. This material science foundation is what enables our radial shaft seals and oil seals to outperform in both standard and customized configurations.
Our oil seal compounds and PTFE-based radial lip seal designs minimize wear at the lip–shaft interface, maintaining stable contact pressure across varying speeds and temperatures.
Find a suitable Simmerring quickly with the Simmerring® Selector.
Radial Shaft Seals – Our Most Important Products Sorted by Application
Automotive Applications
Designed to support energy efficiency and emissions reduction in automotive systems.
Radial Shaft Seals
Freudenberg radial shaft seals solutions are designed to match the specific technical and performance needs of your application. Whether you’re looking for cost-efficiency or maximum durability, FST delivers proven technology, engineering expertise, and application-specific innovation.
CASSETTE Seals:
The wide range of Cassette seals design offer the best performances in terms of dirt protection for every kind of environment, combining the most valuable materials with tailored designs and features.
CASCO® Seal:
Advanced cassette seal with axial lip and metal sleeve, delivering low friction and long service life in diesel and hybrid engines.
Industrial Applications
These seals are engineered for demanding industrial environments, offering high performance in pressure, temperature, and chemical resistance. Across gearboxes, pumps, and electric motors, these oil seals and shaft seals are selected for reliability in contaminated environments and tolerance to misalignment.
Premium Sine Seal (PSS):
Thanks to its unique design and sealing behavior, the Premium Sine Seal from Freudenberg Sealing Technologies can more than double the service life of the sealing system. Our new sealing solution seals reliably, reduces friction and power loss, and actively counteracts internal contamination in the sealing system.
Premium Pressure Seal (PPS):
The Premium Pressure Seal (PPS) is an evolution of the BABSL featuring a patended lip design which keep the lip profile stable up to twice the level of pressure loading of conventional designs.
BABSL Pressure Seal
FST is offering a broad range of standard and customized designs to pressurized applications. The Simmerring® BABSL can be used in many applications with medium pressure like pumps and motors in hydro-units, mechanical power transmission gearboxes, and 2-stroke engines.
MSS1 (Modular Sealing Solution 1):
The MSS1 (Modular Sealing Solution) is a Standard BAUM design, combined with an inner primary seal with sinusoidal sealing lip as one-piece solution. The design is suited for internal dirt contamination protection.
The MSS1 is mainly used in industrial gearboxes, drive technology and robotics.
Gerromatic:
PTFE-based seal designed for chemically aggressive environments such as pumps and compressors.
CASSETTE Seals:
The wide range of Cassette seals design offer the best performances in terms of dirt protection for every kind of environment, combining the most valuable materials with tailored designs and features.
COMBI Seal:
COMBI seals are the best performing sealing product when dirt protection is combined with axial displacement. They're the ideal solution for axles where rotational and axial movement are a need.
CASCO® Seal:
Advanced cassette seal with axial lip and metal sleeve, delivering low friction and long service life in diesel and hybrid engines.
CTIS:
CTIS is a robust radial shaft seal designed for central tire inflation systems, enabling reliable pressure regulation in demanding off-road and on-road conditions.
Discover the new Technical Manual
Become a sealing expert! Our new edition offers an in-depth guide to materials and product expertise, offering a holistic view of sealing technology.
Read now!
Elevate Your Radial Shaft Sealing Systems with Precision Engineering
Discover precision engineering with Freudenberg Sealing Technologies. Our specialized Simmerring® engineering services go beyond selecting top-tier components. We analyze everything to unlock optimal sealing performance. Trust our expertise and commitment to excellence in sealing systems. Harness precision and innovation for peak performance.
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Dichtomatik Radial Shaft Seals
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E-Mobility
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Sealing Solutions for Drive Shafts in the Process Industry
Due to the many different and often unique features of the systems and processes in the pharmaceutical, food and chemical industries, a sealing system with drive shafts can be challenging.
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Simmerring® BAUM RF – an Efficient Sealing Solution For High Speeds
The new Simmerring® BAUM RF (RF = Reduced Friction) is a targeted modification of the classic BAUM design and features a spring with reduced radial force. This adjustment minimizes friction at the sealing lip and reduces the thermal load on both the elastomer and the lubricant – particularly at high circumferential shaft speeds. The result: improved energy efficiency and an extended seal service life.
Simmerring® – the original oil seal
For more than 90 years, the traditional Freudenberg brand CFW® has represented innovation, high-quality and technical excellence of sealing technologies. Best proof is the original Simmerring®, a radial shaft seal developed by Walther Simmer at Freudenberg in 1932, branded CFW® ever since. The Simmerring® has gained worldwide recognition and is used in a wide range of applications.
Overview radial shaft seals
With the "easy to find" radial shaft seal poster, it only takes a second to pre-select the right seal for your application.
Premium Sine Seal (PSS)
Thanks to its unique design and sealing behavior, the Premium Sine Seal from Freudenberg Sealing Technologies can more than double the service life of the sealing system.
Spring-Energized PTFE Seals for Air Conditioning Compressors
Specialized spring-loaded PTFE (polytetrafluoroethylene) seal designed for dynamic scroll-type air conditioning compressor applications for sealing the seal plate to the fixed scroll. Seal design allows for high angles of misalignment without reducing sealing performance. Designed for easy assembly into the housing.
Simmerring® Radial Shaft Seal Standard program Design A/AS
The original Simmerring® is a premium quality radial shaft seal conforming to DIN 3760 and ISO 6194-1 with an elastomeric outer diameter. The Simmerring® can be used in numerous original equipment applications across a broad spectrum of market segments (e.g., gearboxes, transmissions, axles, engines, and pumps).
Simmerring® Standardization
Since 1929, the Simmerring® has stood for outstanding quality and today is known worldwide as a synonym for radial shaft seal rings.
Imperial Standard Range (ISR) Simmerring® Shaft Seals
The Freudenberg Sealing Technologies Imperial Standard Range (ISR) Simmerring® shaft seal is a premium quality seal typically used in applications such as gearboxes, axles, transmissions, and engines.
BABSL Classic Medium Pressure Seal
Medium pressure seals, such as the BABSL, can be used in many applications including pumps and motors in hydro-units, mechanical power transmission gearboxes, and 2-stroke engines.
Premium Pressure Seal (PPS)
Typically, with medium pressure seals, high friction and hollow wear occur due to pressure deformation at the elastomeric flex section of the seal—resulting in an enlarged contact band width.
BlueSeal
The BlueSeal is one design suited for future engine dynamic sealing. This patented radial shaft seal technology offers weight savings of 40 percent compared to a conventional seal, and it requires only half as much installation space.
Radial Shaft Energy Saving Seals, ESS™
Freudenberg Sealing Technologies radial shaft Energy Saving Seals (ESS™), demonstrate significant reduction of power loss in drive assemblies as opposed to standard sealing elements. By combining a special elastomer and a revolutionary new design, this shaft seal is able to maintain the pressure force at a consistently low level over a wide range of RPM, even at a higher sealing operating temperature. The low radial force of the main lip ensures the optimization of sealing function, abrasion resistance, and friction.
High/Low Pressure Seal (HLPS)
The High/Low Pressure Seal (HLPS) from Freudenberg Sealing Technologies is a field-proven, specialty-designed high pressure radial shaft seal. The HLPS is a severe duty pressure seal and has a unique design with several features that greatly improve its overall performance.
The Simmerring® Imperial Standard Range (ISR) Oil Seals
The Freudenberg Sealing Technologies Imperial Standard Range (ISR) Oil Seal is a premium quality seal typically used in applications such as gearboxes, axles, transmissions, and engines.
Low Friction Simmerring®
Values to the customer. ACM 380DF: better relaxation characteristics and bigger temperature range (–40°C to 175°C) compared to classic ACM. Lower friction compared to conventional sealing lip profile: 15 to 20%.
MileMaker
MileMaker is engineered for superior performance. The new MileMaker heavy duty wheel seals deliver significant energy savings and increase the reliability and durability performance expectations for wheel seals in the heavy duty truck and trailer industry.
POP® Seals
The Freudenberg Sealing Technologies PTFE POP Seal is designed for reduced friction in automotive drive assemblies as opposed to standard sealing elements.
Track Roller Seals
Freudenberg Sealing Technologies Track Roller Seals (Floating Seals) commonly used in heavy equipment and construction machinery are noted for their reliable seal endurance characteristics. These durable seals are resistant to moisture, natural contaminants such as sand and fiber, and harsh weather including radical temperature fluctuation, ozone, and extended UV radiation.
Cassette-S4 Seals
The Freudenberg CASSETTE-S4 is the most advanced Freudenberg solution for construction and agriculture mobile machinery wheel hubs and undercarriage applications.
Modification of Simmerrings
Simmerring® features – flexible & application-oriented The Freudenberg Sealing Technologies (FST) catalog program for Simmerrings covers a wide range of sealing applications and we make it possible to optimize existing Simmerrings from our extensive catalog range by making modifications to them.
The Simmerring® MSS 1
The MSS 1 Simmerring® is a unique, patented sealing system with proven functionality in different gearbox and pump applications and with a service life time up to 20,000 hours.
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