
Specializing in Miniature O-Rings
Manufacturer of micro precision o-rings and miniature, custom rubber o-rings. We’ve developed the world’s smallest O-ring, as well as large o-rings with tiny cross sectional diameters. The smallest o-ring in production is ID: 0.196mm C/S: 0.05mm with no parting line. In addition, we can provide smaller o-rings by request. Furthermore, our smallest O-ring developed and tested is ID: 0.05mm C/S: 0.05mm silicone, no parting line.
Smallest O-Ring Developed & Tested
ID: 0.05mm, C/S: 0.05mm, Silicone, No Parting Line
Smallest O-Ring in Production
ID: 0.196mm, C/S: 0.05mm, Silicone, No Parting Line
Quality Micro O-Rings
KEF can provide O-rings “flash free” and with “no parting line” using our high mold technology. Furthermore, we provide dimensional accuracy up to ID +/- 0.01mm C/S +/- 0.01mm. Therefore, we’re able to supply high quality and medical grade o-rings for use in industries such as: medical implant, wristwatch, tooth brush, switch, micro seal, optical, and microscope O-rings, etc. KEF is a leader in custom, miniaturized rubber seals, with over 45 years of experience. We are ISO 9001 and ISO 14001 certified.
Micro O-Ring Materials
KEF develops and produces materials in house, ranging from Silicone, Nitrile, Urethane and more. We work with the latest material innovations, as well as the many thousands of materials we’ve developed in our own database. Furthermore, we provide medical grade FDA (UPS-381) and aviation grade AMS-P-5315. Learn more about our selection of materials (click here).
Styrene-butadiene
Butadiene
Chloroprene
Isobutylene-isoprene
Nitrile
Acrylic
Urethane
Silicone
Fluorocarbon
And more
Customized Miniature O-Rings
We work with our customers to develop all sorts of miniaturized o-rings in various shapes and cross sections. Our specialty is in extremely small o-rings that would otherwise be very difficult to produce. Moreover, our goal is to help you push the limits of design and innovation in medical, electrical, aerospace and more.

Custom Micro O-Rings ID:.010″(0.25mm) By .004″(0.10mm)

Micro O-Rings Sizing

Micro O-Rings High Magnification
In addition, we offer some standard sizes. Learn more about our standard sizes (click here).