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.

A hermetic seal is known as a go-to choice for superior protection when it counts. Whether you require protection from air, gasses, moisture, soil or any other hazard, hermetic connections are the gold standards across many industries. But a seal protects best when it is the right seal for the job. Learn more about the main types of hermetic sealing and find out which ones are best for your job.

To start with, there are three main types of airtight seal. They are:

• Glass to glass seal
• Glass to metal seal
• Ceramic to metal seal

Glass to Glass Hermetic Seals

When two glass pieces require a perfectly sealed environment, glass to glass sealing is the choice. As many as five layers may be involved in the creation this type of seal, which is often used in sealing flat windows, glass tube components and glass envelopes to name just a few applications.

Glass to Metal Seals

Glass and metal fused together to form leak-tight joints are glass to metal seals. These types of seals are all around you every day, due mainly to their versatility and strength.  Known for their exceptional hermetic values, these types of seals are critical in the construction of vacuum tubes, pressure tight glass windows and any number of electronic components to name just a few applications. GTMs are especially useful in the lighting industry, with the most common application being the seal on a lamp bulb.

 Ceramic to Metal Seals

Ceramic to Metal seal is more costly and time consuming to make than a glass to metal seal. Some say it is worth for applications where high operating temperatures, high voltage and harsh environments are required. Ceramic can be made in custom designs and show more resistance to mechanical and thermal shocks.

When zero porosity is required, hermetic sealing is the reliable choice. Know your options by understanding the different sealing possibilities and ensure you’re choosing the best sealing method.