Which Is the Best Hermetic Seal: Glass or Ceramic?

If you are in the market for a hermetic seal, you may wonder if it is better to purchase a glass to metal seal or a ceramic to metal seal. Each variety has its respective advantages and disadvantages. Some people prefer to stick with one kind, while others use different seals depending on the function.

Glass to Metal Seal and Feedthrough

A glass to metal seal is made with glass molten right to the metal. This provides an advantage of a secure seal that is connected directly with the metal. Glass is thought of as fragile, but it has a high level of compression strength. It is also a less expensive alternative to ceramic seals.

Ceramic to Metal Seal

A ceramic to metal seal is more costly than a glass to metal seal, and some say the difference in price is worth it. Ceramic can be made in custom designs and show more resistance to mechanical and thermal shocks. However, these seals can have a greater tendency to chip than glass does, but can last longer before these chips form.

Some people swear by their favorite kind of glass to metal seal, while others prefer ceramic. The kind you choose depends on the job you need to do, cost considerations and how much shock you want the seal to withstand.