Engineering Sealing Solutions That Keep Industries Moving
Founded in 1989, Functional Oil Seal Industrial Co., Ltd. (FOS) is a Taiwan-based manufacturer specializing in high-performance oil seals and precision rubber-to-metal sealing components.
Over the years, we have built our expertise around one clear purpose: to develop sealing solutions that perform reliably under real operating conditions. By combining proven manufacturing experience with continuous engineering development, FOS supports customers in overcoming challenges involving pressure, temperature, friction, wear, media compatibility and service life.
Integrated Manufacturing. Consistent Quality.
Our vertically integrated manufacturing system covers the critical stages of oil seal production, including:
- Metal stamping
- Surface treatment and adhesive application
- NBR and FKM rubber compounding
- Compression molding and vulcanization
- Seal profile finishing
- Garter spring assembly
- Inspection and performance verification
By controlling these processes in-house, we can respond rapidly to new projects, maintain consistent production quality and provide dependable support from initial development to mass production.
More Than Manufacturing
FOS is not simply a producer of standard oil seals. Our capabilities extend to material development, product and tooling design, process optimization, failure analysis and seal performance testing.
We work closely with customers to translate application requirements into practical and manufacturable solutions. Whether the objective is to develop a new seal, improve service life, resolve leakage or wear issues, or stabilize high-volume production, our engineering team approaches every project with technical discipline and a problem-solving mindset.
Quality Built into Every Process
Our management systems are certified to:
- IATF 16949:2016
- ISO 9001:2015
- ISO 14001:2015
These certifications reflect our commitment to automotive-grade process control, consistent product quality, continuous improvement and environmentally responsible manufacturing.
Your Partner in Sealing Innovation
As industries move toward higher speeds, greater efficiency and more demanding operating environments, sealing technology must continue to evolve.
FOS is committed to advancing beyond conventional oil seal manufacturing by developing higher-performance materials, specialized sealing structures and application-specific solutions for the next generation of industrial and mobility systems.
From concept to production, we combine materials, manufacturing and testing expertise to create sealing solutions our customers can trust.
FOS — We engineer confidence into every rotation.

Oil Seals Catagory

External Lip Oil Seals:
- All types are like general purpose types except external lip oil seals.
- Especially designed for sealing rotating housings, e.g. unitized seals, oil bath seals, cassette seals etc.

Dual Lips Seals:
- With the spring loaded, the primary lip retains the fliud in the rigs and preventing leakage.
- Secondary lip would exclude or block dirt entering the rigs.
- Applications which require two fluids from each other, e.g. used for separating ATF oil and differential gear oil.
- Selecting stainless steel spring or case for corrosive medium being sealed.

Flange Case Oil Seals:
- Type J is reverse channel case to accommodate large clearances between the shaft and bore and added a flange and to provide additional strength.
- Type JG is shotgun cases existing a heavy outer flange to strengthen the case.
- There flange case provide the function of positioning the seal, minimizing cocking in the bore and early removing the seal from the bore.
PTFE Lip Seals: Automotive & Industrial Applications
- PTFE sealing lip for sealing aggressive media and sealing areas under high thermal stress.
- PVB1 has a single lip element that combines the low friction properties of PTFE with the flexibility of rubber.
- YPVA . metal encased ptfe rotary lip seal.
- Ptfe lips with OD Case Assembled Seals / Bearings application / Double Ptfe lips Seals / three lips in Ptfe

Competitive Advantages:
- Impressive Professional Technology
- Experienced Technical and Engineered Staffs
- Strict Inspection Procedures
- Regulation Compliance , ESG, PFAS-FREE, SVHC
- High Quality and On-Time Delivery
- Problems identification & Solutions offers
- Seal Design Proposal offers
- In House Sealing Endurance Test
- PPAP Submission,
- Statistical Process Control
- International Standard Criterias

Delivery / Contact Info
- Existing molds: 30 working days, depending on ordering quantity.
- New Molds: 40 working days, depending on ordering quantity.
- Samples Submission : 21-28 working days with existing toolings.
- Address : 21, Tzu Chiang 2 Road, Nankang Ind. Zone, Nan Tou City, 54065 Taiwan. R.O.C.
- Tel : +886-49-2255986
- Fax : +886-49-2255978

Nature of Business / Exporting Markets
- Manufacturer
- EU, U.S.A, ASIA and World Markets
- 98% export