EMI gaskets from Specialty Silicone Products (SSP) combine shielding against electromagnetic interference (EMI) with environmental sealing and thermal and electrical insulation.
SSP fabricates your EMI gasket from shielding silicones and fluorosilicones that are Made in USA. Choose from the following types.
EMI gaskets from SSP provide EMI shielding and environmental sealing in electrical and electronic enclosures. They’re made of silicones or fluorosilicones that are filled with metal or metal-coated particles to provide electrical conductivity.
Ask SSP for standard or custom EMI gaskets, including M83528 part numbers. We offer low minimum order quantities (MOQs) and quick turn-around times for cut or molded parts. Compare our materials to Parker Chomerics CHO-SEAL, Nolato Jabar, and W.L. Gore products.
EMI gaskets seal the gap between two mating surfaces, such as a housing and a lid, in an enclosure. Like other types of environmental seals, they keep out the external environment or seal-in to prevent leakage. What makes EMI gaskets different is that they also seal against conducted or radiated EMI that can interfere with circuits.
When this electromagnetic interference (EMI) or “noise” reaches the EMI gasket, the signals are negated and the resulting electrical current is sent to ground. Silicone is normally an electrical insulator rather than an electrical conductor, but the addition of metal particles imparts the necessary electrical conductivity.
EMI gasket materials from SSP use silicone or fluorosilicone as the base elastomer. They are filled with metal, metal-coated, or bimetallic materials that impart electrical conductivity.
Silicone-based conductive elastomers are widely used because of their excellent temperature range, flexibility, and cost effectiveness. They are suitable for enclosures where shielding and weather resistance are equally important.
Fluorosilicone formulations combine electrical conductivity with exceptional resistance to fuels, solvents, and aggressive chemicals. These EMI gaskets are the material of choice for aerospace, defense, and industrial applications exposed to hydraulic fluids or jet fuel.
SSP offers EMI gaskets that with these electrically conductive fillers:
SSP offers EMI gaskets made from the following types of specialized materials.
Keep reading to learn more, or contact us for a quote.
SSP makes EMI gaskets from materials that are part of the M83528 Qualified Products List (QPL). MIL-DTL-83528 is a U.S. military specification that defines conductive elastomer types and shielding effectiveness levels. Materials on the M83528 QPL meet all MIL-DL-83528 requirements and have been tested by the Defense Logistics Agency (DLA), which is part of the U.S. Department of Defense (DoD).
SSP fabricates EMI gaskets from the MIL-DTL-83528 QPL Certified silicones that we make in Ballston Spa, New York (USA). The table below describes M83528 part numbers, which are also known as slash sizes because of the slash (/) that precedes the final digits.
Specification Sheet | Short Description | Long Description |
M83528/001 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, Circular Strip, .040 Through .250 Diameter. | |
M83528/002 | Gasketing Material, Conductive, Shielding Gasket, Electrical, O-Ring, Standard. | |
M83528/003 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, Solid “D” Shaped Strip. | |
M83528/004 | Gasketing Material, Conductive, Shielding Gasket, Electronic, EMI/RFI, Connector Flange Mount. | |
M83528/005 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, O-Ring, Non-Standard. | |
M83528/006 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, Rectangular, D-Cross Section. | |
M83528/007 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, Hollow D-Strip. | |
M83528/008 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, Hollow P-Strip. | |
M83528/009 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, Solid Rectangular Strips. | |
M83528/010 | Gasketing Material, Conductive, Elastomer, Electrical, EMI/RFI, Channel Strip. | |
M83528/011 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, Hollow O-Strip. | |
M83528/012 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, Electrical, EMI/RFI, Flat Circular Washer. | |
M83528/013 | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, Electrical, EMI/RFI, Waveguide. | |
M83528/014 | Time Totalizing Meter | Gasketing Material, Conductive, Shielding Gasket, Electronic, Elastomer, EMI/RFI, for Use in Time Totalizing Meters Covered by MIL-M-7793. |
SSP’s MIL-DTL-83528 QPL certified EMI gasket materials are shown below. This standard is divided into lettered sections and sometimes written as MIL-G-83528 or M83528. Choose products that meet MIL-G-83528 Type A, B, C, D, or K requirements.
Type | Base Elastomer | Filler | Typical Applications | Key Strengths |
Silicone | Silver-Copper | Aerospace enclosures | High shielding effectiveness | |
Silicone | Silver-Copper | Military electronics | Good balance of shielding and other properties | |
Fluorosilicone | Silver-Copper | Jet fuel environments | High shielding effectiveness | |
Fluorosilicone | Silver-Aluminum | Harsh aerospace environments | Good balance of shielding and other properties | |
Silicone | Silver-Copper | Commercial/industrial | High shielding effectiveness |
Shielding Effectiveness: Up to 110 dB at 10 GHz, depending on material type and filler.
Environmental Sealing: Protects against dust, moisture, and other contaminants while maintaining conductivity.
Wide Temperature Range: Operates from -55°C to +200°C without loss of properties.
Chemical Resistance: Fluorosilicone options withstand fuels, solvents, and aggressive fluids.
Durability: Low compression set and excellent long-term reliability in harsh operating conditions.
SSP EMI gaskets are trusted across industries where performance and compliance matter most:
Defense Electronics: Avionics, radar systems, secure communications.
Aerospace: Satellites, aircraft, spacecraft, and launch systems.
Medical Devices: Imaging equipment, patient monitoring, diagnostic instruments.
Telecom & Networking: High-frequency enclosures, 5G infrastructure.
Industrial Equipment: Automation systems, robotics, and heavy machinery.
Selecting the proper EMI gasket requires balancing shielding effectiveness, compression force, environmental exposure, and cost. SSP can help recommend the optimal conductive elastomer formulation for your enclosure.
For quick reference:
Choose Type A or D for high shielding in aerospace and defense.
Choose Type C for chemical resistance in fuel-rich environments.
Choose Type K when cost efficiency is a priority.
SSP offers more than just standard catalog materials. Engineers can access:
Technical data sheets with full material properties.
White papers on EMI shielding and conductive elastomer design.
Application engineering support to solve challenging EMI and environmental sealing problems.
Ready to get started? Contact SSP to discuss your application or request or quote.
SSP fabricates corrosion resistant EMI gaskets from shielding silicones that we make. They provide resistance to galvanic corrosion, which occurs two dissimilar metals are in contact with each other in the presence of an electrolyte (like water or salt solution) and an electrical current flows between them, causing one metal to corrode preferentially.
SSP’s corrosion resistant EMI gasket materials are shown below. These nickel-aluminum-filled silicones are a cost-effective alternative to silver-filled EMI shielding gaskets. SSP2529 is an offset to CHO-SEAL 6502 and SSP2551 is an offset to CHO-SEAL 6503.
Corrosion resistant EMI gaskets are used in environments where enclosures require EMI shielding and are exposed to harsh environments with moisture, salt, chemicals, or temperature extremes. Other gasket materials can rapidly degrade, but corrosion resistant EMI gaskets maintain sealing and shielding over time. They are used in these and other applications.
Nickel-aluminum-filled silicones exhibit the lowest amount of flange pitting from galvanic corrosion, an electrochemical process that occurs when two different metals are in contact in a saltwater environment. These shielding silicones also exhibit excellent galvanic stability with aluminum flanges.
Soft EMI gaskets are made of soft silicones with durometers as low as 30 Shore A.
They can be made of SSP502-30, a nickel-graphite shielding silicone that is comparable to CHO-SEAL S6305, 6330, 6370, 6371, 6372, and 6308. Also filled with nickel-graphite is SSP502-40 silicone, an offset to CHO-SEAL S6305, 6330, 6370, 6371, 6372, and 6308.
SSP502-40-V0 is a nickel-graphite silicone that is an offset to GORE GS2100 and provides UL 94V0 flame resistance. SSP550-45 is a silver-aluminum fluorosilicone with ASTM E595 low outgassing that is comparable to CHO-SEAL 1287 and 1298.
Like other types of elastomeric gaskets, a soft EMI shielding gasket is compressed by a percentage of its size. This compression forms a seal that physically fills the gap between two surfaces. When the compressive stresses are removed, the EMI gasket is supposed to return to its original thickness. If it does not, this irrevocable deformation (compression set) can leave a gap and cause seal failure.
Harder materials with higher durometers are more difficult to compress, but electrically conductive silicones are not excessively hard because of the addition of particles. In fact, EMI silicones are available in a range of hardnesses, including lower durometers for gaskets where there is less closure force.
Soft EMI gaskets are used in applications that require reliable sealing under low closure force.
Fuel resistant EMI gaskets are made of fluorosilicones for resistance to gasoline, diesel fuel, and aviation fuel (avgas).
Fuel resistant EMI gaskets can be fabricated from a QPL certified MIL-DTL-83528, Type D elastomer and nickel-graphite materials in 50, 60, and 80 durometer (Shore A). SSP also offers two two silver-aluminum fluorosilicones, including a passivated product. Passivation increases the corrosion resistance of the electrically conductive metal particles.
Fuel resistant EMI gaskets are used in military and civilian applications that require resistance to harsh chemicals, including fuels and solvents.
Fluorosilicones combine the high and low-temperature resistance of silicones with the fuel and oil resistance of fluorocarbons. Compounds that are filled with metal or metal-coated particles also provide electrical conductivity and EMI shielding.
Low outgassing EMI gaskets are made of shielding elastomers that meet ASTM E595 requirements for low levels of silicone outgassing, or offgassing, that can occur in vacuum environments like outer space. ASTM E595 is a standard test method that determines total mass loss (TML) and collected volatile condensable materials (CVCM).
SSP’s low outgassing EMI materials include a QPL certified MIL-DTL-83528, Type B offset to CHO-SEAL 1285 and an offset to CHO-SEAL 6502. Low-outgassing flame retardant offsets to GORE GS2100 and GORE GS5200 are also available. In addition, SSP makes shielding gaskets from an EMI silicone for extreme low temperature environments and a silver-aluminum fluorosilicone.
Low outgassing EMI gaskets are used in satellite communications, typically as gaskets for optics, sensors, and electronics that could cloud from silicone outgassing in the vacuum environment of space.
SSP’s most electrically conductive EMI gaskets have silver-coated particles.
SSP’s most electrically conductive EMI gaskets can be made two MIL-DTL-83528 QPL certified EMI silicones that are filled with silver-copper.
There are also three other SSP materials for the most electrically conductive EMI gaskets.
These EMI gaskets are used in a variety of applications that require high levels of electrical conductivity.
The EMI shielding that’s used in automotive, aerospace, and medical electronics must meet multiple design requirements. For example, an EMI gasket that’s used with aircraft may need to resist the splash of jet fuel. Shielding that’s used with EV charging stations may require compliance with UL 94 standards for flammability.
SSP’s flame-retardant EMI gasket materials are made of shielding silicones with a UL 94 V0 flame rating. They contain nickel-graphite particles and meet ASTM E595 requirements for low levels of outgassing.
Use SSP’s flame rated EMI shielding materials instead of GS2100 or GS5200 from W.L. GORE, which discontinued these popular GORE-SHIELD® materials in 2020.
These GORE-SHIELD® materials were approved for military and spaceflight applications.
SSP’s UL 94 V0 flame rated EMI gaskets are used in these and other applications:
Reinforced EMI gaskets contain nickel-graphite particles and are reinforced with an inner layer of conductive fabric. They are fabricated from sheet or rolls materials that come in four different inch-based thicknesses: .020, .024, .032, .040, and .062.
SSP offers two composite materials, both of which have physical properties that are superior to non-reinforced elastomers.
Reinforced EMI gaskets are used in applications where there is a risk of tearing. The conductive fabric layer enhances electrical conductivity and provides mechanical strength and flexibility. They are used in these and other applications.
SSP’s most cost effective EMI gaskets are made from a nickel-graphite EMI silicone.
SSP’s most-cost effective EMI shielding silicone, SSP502-65, supports thinner, smaller, and lighter weight designs. It’s also an offset to CHO-SEAL 6305. This 65-durometer nickel-graphite EMI elastomer offers performance levels that are comparable to shielding silicones with silver-coated particles. Independent test results for salt spray according to ASTM B117 are also available.
These EMI gaskets are suitable for applications where cost is a key consideration. Examples include low-cost electronics such as some mobile devices.
SSP also makes non-silicone EMI gaskets from a 75-durometer nickel-coated EPDM shielding elastomer. As with all SSP’s EMI shielding elastomers, customized versions are available in different durometers.
SSP2514-75 EMI gasket material provides excellent ozone and UV resistance along with good compression set and solvent resistance.
Non-silicone EMI gaskets are used in applications that require:
SSP can flash cut, die cut, or compression mold EMI gaskets from the shielding silicones that we make. SSP can also apply pressure-sensitive adhesive (PSA) backings for ease-of-installation.
Flash cut EMI gaskets use CNC equipment to cut EMI elastomers into specific shapes without custom tooling. Flash cutting is ideal for rapid prototyping and short runs, and this gasket fabrication method produces extremely smooth edges with minimal loss of material. This digital manufacturing process works from your CAD file and supports flash cut EMI gaskets with a conductive PSA.
Die cut EMI gasket materials are cut into specific shapes and sizes from sheets or rolls of EMI elastomers. SSP makes its own dies in-house and fabricates die cut EMI gaskets with a high degree of uniformity, even across higher volumes. Precise dimensions, parts nesting, and punched holes with specific radii are readily achievable. SSP can apply conductive PSA tapes for peel-and-stick parts.
Molded EMI gaskets are produced using compression molding, a process that places a preformed rubber material into the cavity of a heated mold. SSP makes its own molds in-house and produces compression-molded EMI gaskets using the same materials that we supply as sheets, rolls, and extrusions. For large picture-frame style gaskets, molding can increase material yields and reduce material waste.
SSP can also cold bond or splice the EMI extrusions that we flash cut or die cut.
Cold bonding joins EMI materials by using an RTV silicone adhesive or a non-silicone glue. Using a non-conductive adhesive increases the risk of EMI leakage, but conductive glues are available. With non-silicone glues, acrylic adhesives lack the temperature resistance of silicones.
Hot splicing joins EMI materials by applying heat and pressure. A splicing tool, or mold, is required, but hot spliced EMI gaskets have consistent properties throughout. They don’t have a “hard spot” like with a cold bonded EMI gasket either.
SSP supplies mold-able EMI silicones. For frame gaskets, molding minimizes material waste, maximizes material yields, and eliminates the need to bond cut lengths. Fabrication processes like die cutting are efficient, but the cut-out section of a frame gasket can represent significant material waste.
Like other types of elastomeric gaskets, an EMI shielding gasket is compressed by a percentage of its size. This compression forms a seal that physically fills the gap between two surfaces. When the compressive stresses are removed, the EMI gasket is supposed to return to its original thickness. If it does not, this irrevocable deformation (compression set) can leave a gap and cause seal failure.
Harder materials with higher durometers are more difficult to compress, but electrically conductive silicones are not excessively hard because of the addition of particles. In fact, EMI silicones are available in a range of hardnesses, including lower durometers for gaskets where there is less closure force.
EMI gaskets that are made of electrically conductive silicones are installed within enclosures. Examples include electrical and telecommunications equipment, electronic and medical devices, robotic end-effectors, and flat-panel displays.
Some EMI enclosure shielding needs to meet specific requirements for ingress protection (IP) against dust and water.
EMI gasket standards include requirements for EMI shielding and environmental sealing. Some standards, such as NEMA and IP ratings, apply only to environmental sealing but may still affect EMI gaskets made of electrically conductive silicones. In addition to NEMA, the following organizations maintain standards that EMI gasket designers may need to meet.
For some military applications, EMI gaskets must use materials that meet MIL-DTL-83528 requirements. MIL-DTL-83528 is a detail specification from the DoD that establishes general requirements for electrically-conductive elastomeric shielding gaskets. MIL-DTL-83528 contains lettered sections, each of which contains requirements for the base elastomer, durometer, fill material, plane wave shielding effectiveness, and continuous use temperature. Because MIL-DTL-83528 only applies to fill materials that are pure silver or silver-coated, it does not encompass nickel-graphite filled silicones or wire-oriented silicones that contain Monel or aluminum mesh.
UL maintains two flammability standards that may apply to EMI gaskets: UL 94 V0 and UL 50-E. Neither standard is silicone-specific, and both apply to plastics. UL 94 V-0 is part of a larger standard, UL 94, that classifies materials according to how they burn in various orientations and part thicknesses. UL 50E is an IP standard against dust and water that applies to enclosures for electrical equipment that will be installed and used in non-hazardous locations.
For EMI gaskets that require resistance to galvanic corrosion, such as those used in marine environments, ASTM B117 may apply. Galvanic corrosion occurs when two dissimilar metals are immersed in a conductive solution, such as salt water, and are electrically connected. There are also electrically conductive silicones for EMI gaskets that need to meet ASTM E595 for outgassing, a problem in high vacuum environments, such as outer space, where released gases can condense upon and cloud optics.
By their very nature, EVs place a large amount of electrical and electronic content into confined spaces. The radiated and conducted emissions from these systems can disrupt circuits and result in conditions that range from minor inconveniences to dangerous losses of vehicle function. There are sources of EMI outside of the vehicle as well.
Answer: MIL-DTL-83528 is a U.S. military specification that defines performance requirements for conductive elastomer EMI gaskets. It specifies shielding effectiveness, filler types, environmental resistance, and compliance testing. SSP’s QPL-listed EMI gaskets meet these standards for aerospace, defense, and other high-reliability applications.
Answer: EMI gaskets are typically made from conductive silicone or fluorosilicone elastomers filled with conductive particles such as silver-aluminum, silver-copper, or nickel-graphite. The choice of material depends on environmental exposure, required shielding level, and cost considerations.
Answer: SSP’s MIL-DTL-83528 EMI gaskets deliver shielding effectiveness up to 110 dB at 10 GHz, depending on the filler and base elastomer. Performance varies by gasket type and installation method.
Answer: EMI gaskets are essential in aerospace, defense, medical devices, telecommunications, and industrial equipment. They are used anywhere EMI shielding and environmental sealing are required.
Answer: Yes. Conductive elastomer EMI gaskets provide both EMI/RFI shielding and environmental sealing against dust, moisture, and contaminants. Fluorosilicone grades also resist fuels, solvents, and aggressive chemicals.
See these additional resources for more information.
Not all EMI gaskets are made from solid silicones or fluorosilicones.
Beryllium Copper (BeCu) Fingerstock
Pros: Excellent conductivity and spring properties
Use: High-performance RF shielding in enclosures and doors
Metal Mesh Gaskets
Usually made from stainless steel, Monel, or aluminum
Often combined with elastomer cores for compression
Use: Rugged industrial or military environments
Construction: Conductive fabric wrapped over a soft polyurethane or other foam core
Pros: Lightweight, cost-effective, flexible
Use: Consumer electronics, I/O shielding, display bezels
Variants: Different shapes like D-shape, rectangular, or U-channel
EPDM or Fluorosilicone with conductive fillers
Filler Types: Silver, nickel, graphite, etc.
Pros: Better chemical resistance than silicone in some cases
Use: Aerospace, automotive, harsh environments
Construction: Short metal wires (usually silver-plated copper) embedded vertically in a non-conductive elastomer
Pros: High EMI shielding with controlled conductivity
Use: EMI shielding plus environmental sealing (IP-rated applications)
Examples: Silver-filled thermoplastics
Use: Molded or extruded shapes for board-level shielding or custom gaskets
Pros: Moldable into complex shapes, good for low- to mid-level shielding
Combines the strength of wire mesh with compression characteristics of elastomers
Use: High-durability applications like doors or access panels
