EMI Gaskets 

EMI O-rings, EMI shielded gaskets, conductive elastomer flat washer gaskets, jam nut seals, D-subminiature gaskets and EMI shielding products provide protection against unwanted EMI radiation. EMI shielding O-rings and EMI shielded conductive gaskets use electrically conductive CHO-Seal® conductive elastomers from Chomerics for improving electronic device performance. We offer EMI shielding O-rings and EMI conductive gaskets for ruggedized and outdoor EMI shielding applications. Sealing Devices has EMI shielding applications support and engineering assistance for integrating EMI shielded CHO-Seal conductive O-rings, THERM-A-GAP® pads, and thermal management gap fillers.   

Evaluating EMI Shielding Gaskets and EMI O-Ring Effectiveness

Choose EMI shielding O-rings based on the radiated emission spectrum of your equipment and the specifications each unit must meet. EMI O-ring and EMI gaskets provide different levels of EMI shielding effectiveness across a frequency range of 10 kHz to 20 GHz.

EMI Shielding Gaskets and O-rings from Chomerics

  Download Chomerics EMI Engineering Handbook  
for Cho-Seal and Soft-Shield 5000 low closure force fabric over foam conductive gaskets.

EMI Operating Conditions

Many EMI O-rings and EMI conductive gaskets provide a 'best fit' for different operating environmental conditions, including exposure to high and low temperatures, wind and rain, salt spray, solvents and other conditions that can affect the life of EMI shielded gaskets and EMI shielded O-rings.

EMI Mechanical Requirements

The primary goal of an EMI shielded gasket is to seal an electronic enclosure to prevent transmission of electromagnetic interference. Improper design of an EMI seal or enclosure flanges can result in failure. Mechanical design issues must be considered for the proper mating of an EMI gasket with the flanges of an electronic enclosure based on EMI conductive shielding theory.


EMI shielded gaskets require compressive force, and must deflect 30-40% under low closure force to properly maintain contact with mating flanges.

Compression Set

EMI O-Rings EMI shielded gaskets subjected to compressive forces over extended time causes 'deflection' to remain after the load is removed. EMI gasket compression set is an important property when an EMI gasket will be compressed and released regularly in enclosure door and access panel service.

Electrical Stability

EMI gaskets and EMI O-rings provide conductive pathways that electrically bond components to a common ground. EMI shielded gaskets serve as low impedance conductors to improve enclosure reliability.

Installed Cost

EMI gasket installation is a major factor in determining costs. EMI Shielded gaskets can be installed using PSA's, fasteners, epoxies, or press-fitting into grooves. EMI gaskets can be molded in place on the enclosure flange or plastic spacer frame.

Gasket Mounting Choices

EMI gasket mounting techniques offer cost-effective choices in materials and assembly. EMI shielded Chomerics gaskets attach easily, and our Engineers can provide details on EMI gasket mounting.

Finding EMI shielded conductive O-rings and EMI elastomers for effective EMI shielding using CHO-Seal® Soft-Shield®, Metal EMI Gaskets, Fingerstock and EMI low closure force gasketing from Chomerics for your wireless communications or enclosures has never been easier. Need help with EMI conductive shielding theory? Review with our experienced EMI theory Applications Engineers today, or download the Chomerics design information highlighting EMI conductive shielding theory.

Cho-Seal, Soft-Shield,Therm-a-Gap, Cho-Therm and Win-Shield are registered trademarks of Parker Hannifin Corp.

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PSA emi shielding options

Pressure Sensitive Adhesive

Quick efficient attachment strip

Friction Fit in Groove EMI shielding

Friction fit in a groove

Prevents over-deflection of gasket. Retaining groove required

EMI Adhesive Compounds

Adhesive Compounds

Conductive of non-conductive spot bonding

Form-in-place robotically dispensed gaskets

Robotically Dispensed Formed-in-Place Conductive Elastomer

Chomerics' Cho-Form™ automated technology applies high quality conductive elastomer gaskets to metal or plastic housings. Manufacturing options include Chomerics facilities, authorized Application Partners, and turnkey systems.

Friction fit on tangs

Friction Fit on Tangs

Accommodates thin walls, intricate shapes

EMI Spacer gaskets

Spacer Gaskets

Accommodates thin walls, intricate shapes

Fully customized, integral conductive elastomer and plastic spacer provide economical EMI shielding and grounding in small enclosures. Locator pins ensure accurate and easy installation, manually or robotically.


Chomerics Conductive Elastomers


Require integral compression stops

Require mounting holes on flange

Chomerics Frame Gaskets


Extruded aluminum frames and strips add rigidity