The World’s Smallest O-Ring

Innovative designs are becoming smaller and smaller, and as a result, the market demand for miniature components is growing. Hence, our team has accepted the challenge to develop the world’s smallest o-ring! We specialize in extremely tiny o-rings and custom rubber seals, therefore allowing us to meet the intricate needs of our customers.

We’ve Created The World’s Smallest O-Ring!

After much development work, we’re thrilled to share the world’s smallest o-ring. This component is molded from clear silicone, and furthermore flash free and with no parting line. Both diameter and cross section are .002″ – That’s smaller than a human hair!

Smallest O-Ring Developed & Tested
ID: .002in (0.05mm), C/S: .002in (0.05mm),
Silicone, No Parting Line

Smallest O-Ring in Production
ID: .008 in (0.196mm), C/S: .002in (0.05mm),
Silicone, No Parting Line

The World's Smallest O-Ring

Specializing in Tiny O-Rings and Custom Seals

KEF is a leading provider of extremely small and precise custom rubber products. We have over 50 years of expertise, helping our customers develop extremely small and precise seals. Consequently, our expertise can decreased costs, and lead to quicker times to market. We’re ISO 9001 and ISO 14001 certified, and furthermore specialize in high quality seals for the medical and aerospace industry. Above all, we’re here to help our customers push the limits in design and develop high quality products. Learn more about our micro miniature or-rings.

Custom made, Odd Shaped, Tiny Seals
High Precision Vibration Insulators
Custom Micro Diaphragms
Chemical Resistant Seals
Class 100 Clean Room
ISO 9001 and ISO 14001

Micro Sealing Materials

We supply a wide array of materials and rubbers, therefore allowing flexibility to meet your design needs. Micro o-rings are typically molded from silicone, but can furthermore be molded from Nitrile, Chloroprene, Acrylic, and more. Additionally, we supply FDA grade rubber materials to meet strict medical device requirements. With advances in technology, miniaturization has become ever more prevalent. As a result, we’ve formulated a vast array of materials to help meet your needs. Learn more about our rubber molded materials.

Standard Micro O-Rings

In addition to our custom molds, we provide some standard sizes as well, which are sized as small as ID: .029″ (0.74mm), CS: .040″ (1.02mm). Learn more about our standard sizes.

KEF develops O-ring for Pacemaker

pacemaker o-rings

This requires strict industry standards and that each part will meet or exceed those standards, time after time. Making material with high precision and high reliability is a critical issue. It is also critical in our O-rings.

KEF develops fuel pump diaphragms for aviation jet engine

o-rings for fuel pump

This was no easy task. Diaphragm thickness and diameter are 0.025″±0.004 and 2.840″ respectively with nylon cloth inside. 
aerospace diaphragm
The three-layer structure is created by compression molding on both sides of a nylon cloth with special rubber that we have developed. This diaphragm sends fuel to the engine using pressure fluctuation –very thin. However, high durability is required.

KEF develops wristwatch seal for ASTRONAUT’S use

aerospace o-rings

Accuracy and reliability are important for use in space. This watch seal’s specifications are waterproof up to 1000 meter deep and must withstand temperatures of -20°C~+70°C. A product is developed using our newest raw material compound, proving high quality and reliability. Since Oct. 2008, astronauts have used this inside and outside of a spacecraft, and the exact time is displayed continuously.