M83528 Connector Gaskets for EMI Shielding is the first in a series of technical articles about why defense contractors are sourcing EMI connector gaskets made of particle-filled silicones. For over 25 years, Elasto Proxy has custom-fabricated seals, gaskets, and insulation for the North American defense industry.
Defense contractors need conductive elastomeric gaskets that resist electromagnetic interference (EMI), provide environmental sealing, meet military specifications, and help contain project costs. Elasto Proxy custom-fabricates EMI shielding, including M83528 connector gaskets, that meet all of these requirements. Using water jet cutting, we convert particle-filled silicones, specialized elastomers that combine the electrical properties of metals with the environmental resistance of silicone rubber. We also offer various splicing and taping methods for M83528 connector gaskets.
M83528 Connector Gaskets and Particle-Filled Silicones
The shielding elastomers that Elasto Proxy custom-fabricates for M83528 connector gaskets use silicone or fluorosilicone as the base material. Silicone offers thermal stability over a wide temperature range and resists water, ozone, and ultraviolet light. With its fluorine additions, fluorosilicone adds resistance to solvents and jet fuels. Shielding elastomers are available in a range of durometers, including ultra-soft silicones. For added strength, particle-filled elastomers can be reinforced with an inner layer of conductive fabric.
Fill materials for shielding silicones and fluorosilicones include metal or metal-coated particles that provide electrical conductivity and EMI shielding. Some older part drawings still specify silver-filled products, but silver-aluminum silicones offer excellent conductivity and strong volume resistivity, an indirect measure of shielding effectiveness. Importantly, shielding elastomers with silver-coated fills cost significantly less than pure-silver products. The following table explains.
| Filler Type | Cost | Electrical Conductivity |
Typical VR
(ohms/cm) |
| Silver | $$$$$ | Extremely Conductive | .0009 |
| Silver-Aluminum | $$$$ | Super Conductive | .003 |
| Silver-Copper | $$$$ | Super Conductive | .003 |
| Silver-Glass | $$$ | Very Conductive | .006 |
| Nickel-Graphite | $$ | Conductive | .01 |
| Carbon Black | $ | Semi-Conductive | 8.0 |
M83528 Connector Gaskets and QPL Materials
MIL-DTL-83528 (M83528) is a U.S. military specification (MIL-SPEC) for electrically-conductive, elastomeric shielding gaskets that suppress EMI and radio frequency interference (RFI). This MIL-SPEC consists of lettered sections (Types A through M) that establish minimum levels of plane wave shielding effectiveness at 10 GHz over a continuous-use temperature range. MIL-DTL-83528 also defines the base material and the fill material for each Type. As noted above, fill material is an important driver of EMI gasket costs.
Elasto Proxy custom-fabricates EMI gaskets from shielding elastomers that meet the requirements of MIL-DTL-83538 Types A, B, D, E, L, K, and M. Two of the compounds that we convert have a Qualified Project Listing (QPL) from the Defense Logistics Agency (DLA), part of the U.S. Department of Defense. These QPL listed materials have been independently tested for best attenuation level, as reported below.
The following table describes the M83528 connector gaskets that Elasto Proxy custom-fabricates.
| MIL-DTL-83528 Type |
EMI Gasket Material | Fill Material |
Base Elastomer | Durometer (Shore A) | VR (Ohms/Cm) | QPL? | Shielding Data? |
| A | EMI-83528-A-65 | Silver-Copper | Silicone | 65 | .0009 | ||
| B | EMI-83528-B-65 | Silver-Aluminum | Silicone | 65 | .001 | Yes | Yes
139.1 dB @ |
| D | EMI-83528-D-70 | Silver-Aluminum | Fluorosilicone | 70 | .005 | Yes | Yes 137.4 dB @ 80 MHz |
| D | EMI-83528-D-45 | Silver-Aluminum | Fluorosilicone | 45 | .002 | ||
| D | EMI-83528-D-70P* | Silver-Aluminum | Fluorosilicone | 70 | N/A | ||
| E | EMI-83528-E-65 | Silver | Silicone | 65 | .001 | ||
| L | EMI-83528-L-75 | Silver-Nickel | Silicone | 75 | .001 | ||
| K | EMI-83528-K-80 | Silver-Copper | Silicone | 80 | .0009 | ||
| M | EMI-83528-M-65 | Silver- Glass |
Silicone | 65 | .006 |
* EMI-83528-D-70P* is passivated for increased corrosion resistance.
Supporting Military Electronics and Your Informational Needs
Thank you for reading this technical article about M83528 connector gaskets. Future articles will explain how Elasto Proxy also fabricates military EMI gaskets that do not need to meet MIL-DTL-83528 requirements. We’ll also describe the cost-saving benefits of water jet cutting, splicing, and taping. Finally, other articles in this series will take a closer look at the advantages of EMI connector gaskets made from specific materials, such as ultra-soft silicones, conductive-fabric reinforced silicones, and QPL listed products.
Contact Us and Then Visit Us at CANSEC 2016 (Booth #935)
Do you have questions about EMI connector gaskets? Please contact us, and then visit us at CANSEC 2016 in Booth #935 from May 25 – 26, 2016 at the EY Centre in Ottawa.
