Hermetic Seal Connectors — Glass-to-Metal Seal, Lightweight Hermetic, and Military-Grade Air-Tight Interconnects

Qualified Military and Commercial Hermetic Connectors for Harsh-Environment, Air-Tight-Seal Applications

Hermetic connectors are highly engineered Mil/Aero interconnect devices designed to maintain an air-tight seal in extreme environments. Using glass-to-metal sealing or advanced encapsulant technology, these hermetic seal connectors prevent moisture ingress, resist pressure differentials, and protect sensitive electronics in mission-critical systems. From submarines and oil-and-gas equipment to orbiting satellites, laboratory vacuum chambers and commercial or military aircraft, hermetic connectors ensure long-term reliability wherever environmental sealing is essential.

Glenair supplies a broad range of hermetic seal connectors — including MIL-DTL-38999 Series I, II, III, and IV — originally developed for military aerospace hermeticity requirements. Today, these ruggedized, air-tight connectors are also widely used in commercial sectors such as energy exploration, industrial instrumentation, and medical devices.

Engineered for extreme application conditions, Glenair hermetic connectors safeguard high-value payloads and electronics in environments characterized by severe weather, high altitude, rapid temperature changes, and vacuum exposure. Applications include sealed black-box enclosures, UAV payload systems, precision sensors, and other electronics that depend on consistent pressure-tight and moisture-barrier performance.

While glass-to-metal sealing remains the industry benchmark, Glenair’s next-generation CODE RED™ encapsulant hermetic technology offers mission-critical sealing with improved electrical performance and significant weight reduction — a major advantage in modern aerospace and unmanned systems.

Zero or Near-Zero Gas Leakage (Hermeticity)

Both Glenair CODE RED and glass-to-metal seal hermetic connectors deliver a qualified air-tight seal to prevent the passage of gases — not just liquids — through the connector interface. In Mil/Aero hermetic connectors, this is quantified using leak-rate limits such as:

• ≤ 1×10^⁻⁷ atm-cc/sec helium
• Verified via helium fine-leak and gross-leak testing
• Rated operating temperatures -115°C to 200°C (-175°F to 392°F)

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NASA Hermetic Standards

Glenair supplies hermetic feed-thrus and hermetically-sealed receptacle connectors that meet the following NASA standards for interconnects used in manned spacecraft:

• NATC (NASA Threaded Coupling)
• SSQ21635 (NASA standard for circular, mostly hermetically sealed connectors used in manned spacecraft)
• NASA-STD-8739 (NASA assembly standard for cable systems on the ISS, ESCC manufacturing standards are compliant)

Military Standard Hermetic Connector Configurations Include:

• Hermetic power inserts based on MIL-DTL-5015 in shell sizes 25L to 37
• Signal hermetic designs IAW MIL-DTL-38999 Series I, II, III, and IV
• Rectangular MIL-DTL-24308 hermetic receptacles
• MIL-PRF-83513 type Micro-D hermetic connectors
• MIL-DTL-26482 Series I and II type power and signal hermetic designs
• MIL-DTL-83723 Series III threaded and bayonet hermetics

Glenair Signature "Better-than-QPL" Hermetic Connector Configurations Include:

• Series 80 Mighty Mouse Lightweight Circular Hermetics
• Series 806 Mil-Aero Micro Miniature Hermetic IAW MIL-DTL-38999 Series III
• HiPer-D MIL-DTL-24308 Intermateable Hermetic Connectors
• Series 79 High-Density Hermetic Rectangular Connectors
• PowerTrip High-Density Hermetic Circular with Power Inserts
• Geo-Marine Harsh-Environment Hermetic Connectors

Mil-Qualified and Glenair Signature Hermetic-Class Connector Datasheets

• Glass-to-Metal Seal Configurations
• Lightweight CODE RED Encapsulant Seal Configurations

Introduction to Hermetic Seal Connectors

• Introduction to Glenair Hermetic Seal Connector Products
• Space-Grade Application Guidelines for Hermetic Connectors
• Hermetic Connector Helium Leak Rates and Testing
• Hermetic Connector Designer's Application Checklist

Hermetic Connector Modification Codes

• Special Leak Rate Modification Code 585 and Dual O-Ring Material Designation Mod Code 1358

PC Tail Termination Note

To prevent detrimental intrusion of cleaning solvents/water into the connector when terminating, the connector must be protected IAW IPC J-STD-001 and/or NASA STD-8739.3. For assistance and/or additional information, please contact factory.

Related Glenair Connectors

• CODE RED™ Lightweight Hermetic Sealing Connectors
• Miniaturized Circular Connectors (38999, 28840, 5015, and Other Cylindrical Designs)
• Rugged Connectors for Geophysical and Offshore Applications