Top 5 Glass to Metal Seal Manufacturers in the World 2025
Release time：2025-04-14
In high-reliability industries like aerospace, defense, automotive, energy, and medical technology, precision sealing is critical. One solution that stands out for durability and performance is the glass-to-metal seal (GTMS). These hermetic seals ensure airtight, moisture-proof, and pressure-resistant connections between electrical components and harsh environments.
To help businesses and engineers choose the best partner, we’ve compiled a list of the Top 5 Glass-to-Metal Seal Manufacturers in the World. These companies are recognized for their advanced engineering, production capabilities, and commitment to sealing performance.
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Top Manufacturers 1. Legacy Technologies 2. SCHOTT 3. Concept Group 4. SPCERA 5. Electrovac |
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Key Product Offerings - Hermetic feedthroughs - TO headers - Sealing glass - Battery end caps - Ceramic-to-metal seals |
Selection Criteria - Engineering expertise -Certifications (MIL-STD, ISO, RoHS) -Customization capability - Global service coverage |
1. Legacy Technologies LLC
Legacy Technologies is a leading American manufacturer of glass-to-metal hermetic seals, headers, and feedthroughs. With decades of experience in defense, aerospace, and electronics, they provide custom-engineered solutions with tight tolerances and high-pressure resistance.
Highlights:
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MIL-STD and aerospace-grade certified
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Hermetic feedthroughs, glass-to-metal headers, and connector seals
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Customized solutions for extreme temperature and pressure
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Strong R&D for mission-critical components
Legacy’s seals are used in satellites, avionics, power supplies, and defense-grade electronic systems.
2. SCHOTT AG
SCHOTT is a global pioneer in specialty glass and glass-to-metal seal technologies. With over a century of experience, which supplies hermetic sealing products for medical implants, aerospace connectors, energy storage, and semiconductor packaging.
Highlights:
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Global manufacturing in 30+ countries
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TO headers, glass tubes, and high-voltage feedthroughs
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Widely used in pacemakers, battery cells, satellites, and telecom equipment
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Known for ultra-reliable hermetic glass technology
SCHOTT’s GTMS solutions set the global benchmark for medical and aerospace-grade sealing.
3. Concept Group LLC
Concept Group specializes in glass-to-metal and ceramic-to-metal seals for military, defense, and aerospace sectors. Their expertise lies in customized solutions, small-batch prototyping, and high-precision feedthroughs.
Highlights:
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Multi-pin connectors and high-frequency GTMS assemblies
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ISO 9001:2015 certified manufacturing
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Complete hermetic packaging services including brazing and testing
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Custom builds for extreme environments
Concept Group is ideal for companies that need tailored, small-volume hermetic sealing solutions with strict technical requirements.
4. SPCERA
SPCERA is a rapidly growing Chinese manufacturer offering glass-to-metal seals, battery end caps, sealing glass, and ceramic sealing solutions. With a focus on cost-effective, high-performance materials, SPCERA serves industries such as lithium batteries, electronics, and industrial sensors.
Highlights:
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Custom sealing glass (e.g., Kovar sealing glass, iron sealing glass)
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Advanced ceramic-to-metal and vacuum sealing systems
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Applications in EV batteries, semiconductor packaging, medical devices
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Offers low-leakage, high-temperature-resistant end caps
SPCERA is especially competitive in customized sealing solutions for OEMs and battery manufacturers worldwide.
5. Electrovac Hermetic Packages GmbH
Electrovac is a trusted European provider of glass-to-metal and ceramic-to-metal hermetic packages, serving automotive, medical, sensor, and industrial markets. With global production capabilities, Electrovac is known for precision sealing, multilayer ceramics, and brazed connectors.
Highlights:
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70+ years of hermetic sealing experience
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Cleanroom production, high-voltage insulators, and laser-welded headers
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Used in laser devices, EV batteries, industrial sensors, and defense systems
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Dual manufacturing sites in Austria and the U.S.
Electrovac’s engineering team supports both mass production and highly customized sealing requirements.
Glass-to-Metal Seal Manufacturers – Comparative Analysis Chart
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Manufacturer |
Core Products |
Specializations |
Key Industries |
Certifications / Standards |
Website |
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Legacy Technologies LLC |
Glass-to-metal hermetic seals, headers, feedthroughs |
MIL-spec components, high-pressure sealing, defense-grade feedthroughs |
Aerospace, Defense, High-Reliability Electronics |
MIL-STD, ITAR, RoHS |
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SCHOTT AG |
TO headers, glass tubes, high-voltage feedthroughs, GTMS |
Medical hermetic seals, battery headers, semiconductor packages |
Medical Devices, Aerospace, Energy, Telecom |
ISO 9001, ISO 13485, MIL-STD, REACH |
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Concept Group LLC |
Hermetic connectors, glass-to-metal seals, brazed components |
Low-volume, high-precision prototyping, custom configurations |
Military, Aerospace, R&D, Specialty Connectors |
ISO 9001:2015 |
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SPCERA |
Sealing glass (Kovar, iron), battery end caps, ceramic-metal seals |
Custom glass-to-metal seal design, battery sealing components, vacuum sealing materials |
Batteries (Li-SOCl₂), Sensors, EV, Semiconductor |
In-house specs, RoHS, ISO-like practices |
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Electrovac GmbH |
Metal-glass seals, multilayer ceramic packages, laser-welded connectors |
High-reliability industrial seals, automotive sensors, cleanroom manufacturing |
Automotive, Medical, Industrial, Sensors |
ISO 9001, ISO/TS 16949, VDA 6.1 |