EMI connector gaskets

EMI Connector Gaskets

SSP makes EMI connector gaskets for electrical and electronic connectors used in harsh environments and demanding applications.

We make standard and custom products from the EMI silicones we manufacture in Ballston Spa, New York (USA). Many of our materials are MIL-DTL-83528 QPL certified.

SSP makes connector gaskets in M83528/004 slash sizes. We also offer EMI gaskets for other types of connectors used in defense, aerospace, medical devices, robotics, and unmanned systems.

Environmental Sealing and EMI/RFI Shielding

SSP makes EMI connector gaskets that provide both environmental sealing and shielding against electromagnetic interference (EMI). Unlike standard connector gaskets, our products reduce or eliminate the transmission of EMI through the connector or between connected devices.

At our Made in USA manufacturing facility in Ballston Spa, New York, we cut or mold EMI connector gaskets from the electrically conductive silicones that we make. We offer lower minimums and faster turnaround times than you’ll find elsewhere. 

EMI Connector Gasket Guide

SSP makes the following types of EMI connector gaskets.

Type

Description

M83528/004

Made from EMI/RFI shielding silicones that are part of the M83528 Qualified Products Lists (QPL) from the U.S. Defense Logistics Agency (DLA). SSP’s Type A, B, C, D, and K elastomers provide offsets to Parker Chomerics CHO-SEAL and Nolato Jabar products. 

Circular

Designed for rugged circular connectors that resist shock vibration, and contaminants. They typically contain a locking mechanism and are used for power, signal, and data transmission in harsh environments.

D-Subminiature (D-Sub)

Used with D-subminiature (D-sub) connectors, components for reliable data, signal, and power transmission in computers, industrial control and communication. AMPLIMITE from TE Connectivity is a common brand name for these connectors.

Micro-D

Used with Micro-D connectors and provide sealing and shielding in harsh, space-constrained environments. Micro-D connector manufacturers include NICOMATIC, Omnetics, and AvioRace. Defense and aerospace applications include avionics, missiles, and unmanned aerial vehicles (UAVs)

MDM

Used with a specific, high-performance line of Micro-D connectors for defense and aerospace applications and may meet MIL-DTL-83513 requirements. MDM connectors are similar to and sometimes interchangeable with Micro-D connectors; however, these components are not the same. MDM connector manufacturers include Glenair and ITT Cannon. 

Nano-D

Used with Nano D connectors, which feature an ultra-small, D-shaped design. These connectors are used in military, aerospace, satellite, medical, and robotics applications where size, weight, and power (SWaP) are critical. They are significantly smaller than Micro-D and standard D-sub connectors and may meet MIL-DTL-32139 standards. Omnetics is a leading Nano-D connector manufacturer. 

BNC

Used with BNC connectors and feature a secure, twist-to-lock mechanism. They are used in RF applications such as computer networking and video transmissions, and in industrial test equipment like oscilloscopes. Their bayonet locking mechanism ensures a vibration-resistant connection that snaps into place quickly and is also easy to disconnect. 

NASA Spec

Also known as space-grade connectors, they are designed and qualified to meet the requirements of space applications on spacecraft and satellites. They are built to withstand harsh conditions like extreme temperatures, shock, and vibration, and must pass stringent tests for properties like outgassing and residual magnetism, which could interfere with other equipment. 

MIL-C-38999

Miniature, circular connectors for reliable connections in harsh environments with extreme temperatures, vibration, moisture, and corrosion. They are used with MIL-C-38999 connectors, which are now known as MIL-DTL-38999 connectors. MIL-DTL-38999 connector gaskets feature secure coupling mechanisms and are used with aircraft, ships, tanks, and satellites.

MIL-C-26482

Specialized components for miniature, circular, bayonet-style military connectors. Applications for MIL-C-26482 connectors include military vehicles, ground support equipment, aircraft, radar systems, and vacuum chambers. Some connector designs feature integrated grommets for wire sealing.

MIL-C-5015

Hheavy-duty, circular connectors that are used in military, aerospace, industrial, rail, robotics, and heavy equipment applications. MIL-C-5015 has been superseded by MIL-DTL-5015 and derivatives such as SAE-AS50151; however, many modern connectors are designed to mate with older MIL-C-5015 connectors.  

MIL-C-8723

Meet the requirements of a U.S. military specification (now MIL-DTL-83723) for environmentally sealed circular electrical connectors that feature bayonet or threaded couplings. Applications include aircraft, ground vehicles, and telecommunications. Like the connects that house them, MIL-C-83723 connector gaskets withstand harsh conditions. 

ARINC

Used with connectors such as ARINC 600, a standard for avionics rack and panel connectors. They resist vibration and extreme temperatures, and feature environmental or hermetic sealing for protection against moisture, jet fuel, or other fluids. ARINC connector manufacturers include Amphenol, TE Connectivity, and PEI-Genesis.

LEMO

Designed for LEMO connectors, a type of high-quality connector that’s known for its push-pull latching system. Due to their ruggedness, these connectors are used with industrial automation, aerospace, scientific research, and medical applications, including imaging, monitoring, and surgical equipment. 

MTC

Modular, miniature rectangular connectors that are designed for environmentally sealed applications. These electrical connectors prevent moisture, dust, and other contaminants from entering the connector system where it joins a cable or housing. Connector manufacturers include TE Connectivity and Amphenol.

Material Comparisons and Performance Capabilities

SSP makes EMI connector gasket materials that use silicone or fluorosilicone as the base elastomer and are filled with metal or metal-coated particles. We can help you to select the best material for your application. Contact us for assistance.  

Material

Shielding Effectiveness

Durometer

Fuel/Oil Resistance

Temp Range

Meets MIL-DTL-83528

Silver‑Aluminum Silicone

90–120 dB

65–75

Moderate

–55 to +160°C

Yes

Silver‑Aluminum Fluorosilicone

90–120 dB

70–80

Excellent

–55 to +200°C

Yes

Nickel‑Graphite Silicone

80–100 dB

65–75

Good

–55 to +160°C

Yes

Silver‑Copper Silicone

100–120 dB

65–75

Moderate

–55 to +160°C

Yes

Silver‑Nickel Silicone

110–130 dB

65–75

Good

–55 to +160°C

Yes

How EMI Connector Gaskets Work

EMI/RFI connector gaskets provide both electromagnetic shielding and environmental sealing at the interface between a connector and its mounting surface.

Shielding Mechanism

  • Conductive elastomers create a continuous conductive path between the connector shell and the enclosure.
  • This forms a Faraday cage, preventing electromagnetic energy from entering or escaping the system.
  • Proper compression ensures low contact resistance and stable shielding performance.

Environmental Sealing

  • Silicone and fluorosilicone bases provide:
    • Moisture sealing
    • Dust and particulate protection
    • Chemical and fuel resistance
    • Long‑term compression set resistance

Why Compression Matters

  • EMI gaskets require uniform compression to maintain conductivity.
  • Over‑compression can damage the gasket; under‑compression reduces shielding effectiveness.
  • Compression‑stop designs eliminate torque‑related failures.

Galvanic Compatibility Guide

Galvanic corrosion can degrade shielding performance and shorten gasket life. Material selection should match the connector shell and enclosure metals. SSP makes corrosion resistant EMI gasket materials, and we fabricate these materials into connector gaskets.

Recommended Pairings

Housing Material

Recommended Gasket Material

Notes

Aluminum (Alodine/Anodized)

Silver-Aluminum Silicone

Best match for similar galvanic potential

Stainless Steel

Silver‑Nickel Silicone

Prevents dissimilar metal corrosion

Magnesium Alloys

Nickel‑Graphite Silicone

Reduces galvanic mismatch

Titanium

Nickel‑Graphite or Silver‑Nickel

Stable in aerospace environments

Composite Enclosures

Any conductive elastomer

No galvanic interaction

Failure Modes to Avoid

  • Pitting corrosion
  • Increased contact resistance
  • Loss of shielding effectiveness
  • Mechanical degradation at the interface

Dimensional Guidance and Part Drawings

Typical Connector Gasket Dimensions

Most EMI connector gaskets follow:

  • Standard circular connector OD/ID profiles
  • Bolt‑pattern alignment for MIL‑spec connectors
  • Thicknesses from 0.020″ to 0.125″

Note: Custom thicknesses available for non‑standard compression requirements

Send SSP your drawings so we can provide you with a connector gasket quote.

How to Select the Right Connector Gasket

  • Connector Type: Match the MIL‑SPEC series or commercial connector geometry.
  • Shielding Requirements: Determine the required attenuation (typically 80–120 dB). Higher frequencies may require silver‑nickel or silver‑copper.
  • Environmental Exposure:
    • Fuel/oil exposure needs Fluorosilicone.
    • Salt fog / marine environments need Silver‑Nickel.
    • General electronics needs Nickel‑Graphite or Silver‑Aluminum
  • Compression Requirements: Consider torque limits and need for compression stops.
  • Galvanic Compatibility: Match gasket filler to housing metal to prevent corrosion.

Manufacturing and Customization Capabilities

SSP provides full in‑house manufacturing for EMI/RFI connector gaskets:

  • Precision molding for circular and rectangular profiles
  • Custom geometries for non‑standard connectors
  • Rapid prototyping for development programs
  • In‑house material compounding (conductive silicone & fluorosilicone)
  • Shielding effectiveness testing
  • Compression set and environmental testing
  • Short‑run and high‑volume production

Contact SSP for a quote.