Glass-to-Metal Seals

The Fredericks Company offers comprehensive technical services and support for OEM manufacturers looking to develop sophisticated glass components. Whether it is glass pinch or press stems with metal leads, glass-to-metal feedthroughs or custom tubulations with metal flares or flanges, The Fredericks Company will provide you with the highest quality precision product with vacuum-tight seals.

Utilizing our expert glass techniques and unique methods and equipment developed over decades, The Fredericks Company specializes in sealing to Kovar metal, sapphire and platinum, but our entire glass-to-metal sealing capabilities include the following materials:

  • Soft glass
  • Tungsten
  • Hard glass
  • Sylvania #4
  • Pyrex®
  • Kulgrid
  • Uranium
  • Molybdenum
  • Nonex
  • Titanium
  • Kovar
  • Platinum


Fredericks’ extensive in-house design and fabrication allows us to customize your product to fit your specific need. Technical capabilities include:

  • High-speed forming
  • Traditional and automatic lathe fabrication
  • Multi-element sealing
  • RF Sealing Gold, silver and platinum surface metalizing


Our products have been used to support numerous applications including cathode ray tubes, x-ray tube image intensifiers, laser and infrared detectors, photomultipliers, and evacuation and getter-firing electron and power tubes. Whatever glass-to-metal design you have, contact our glass engineering specialists for an appraisal and determination of how we can address your needs.