What’s the Difference Between a Gasket and a Seal?

Gaskets, Specialty Rubber

It is a common misconception that gaskets and seals are the same thing.

While it is true they perform similar functions in preventing leaks, gaskets and seals have distinct applications. Generally speaking, gaskets serve as a static seal between flat surfaces, such as joints, while seals are used in more dynamic environments between active components such as rotating shafts, pumps, and engines.

What Is a Gasket?

Rubber gaskets from aero rubber in a variety of shapes

A gasket is a ring or sheet composed of a supple material used in static applications to seal joints, flanges, and other mating surfaces to prevent leakage.

Depending on the material and application, gaskets can be produced using a broad range of manufacturing techniques, including:

Both gaskets and seals can be found in nearly every application and industry, including oil and gas, manufacturing and industrial applications, pulp and paper production, and agricultural equipment.

Worn or broken gaskets are easy to replace. It is typically recommended to change gaskets any time the equipment is disassembled and reassembled.

What Is a Seal?

Rubber seals from aero rubber

Seals are a broader category that includes o-rings, valve stem seals, rotary seals, and mechanical seals. Unlike gaskets, which are typically used for static applications, seals are found in more active environments in motors, engines, pumps, and rotary shafts. Seals tend to be flat and round, with a tilted inner ring of rubber surrounded by a metal outer ring. The tilted angle of the seal’s inner layer helps to prevent leakage in dynamic applications. Seals are typically used to prevent leaks between two moving parts, and to prevent the intrusion of particles and contaminants into the system.

The process for replacing a broken or damaged seal can be very involved. Not only the seal, but the entire assembly may need to be dis-assembled to get access to the seal and allow for replacement.

Gasket and Seal Materials

Seals and gaskets can be made of a broad range of materials, depending on the applications for which they will be used. Common materials used to make both gaskets and seals include:

  • Buna ‘N’ (Nitrile)
  • CSR (Hypalon®)
  • EPDM
  • Flourosilicone
  • Fluoroelastomer (FKM)
  • Natural Rubber (polyisoprene)
  • Neoprene
  • Polyurethane
  • Silicone
  • Synthetic Polyisoprene
  • Thermoplastic Rubber (TPR)
  • Viton®

All of Aero Rubber’s materials can be formulated and customized to meet the needs of your specific application.

Guide to choosing elastomers - Rubber material selection guide by Aero Rubber

Explore Aero Rubber’s Guide To Selecting Elastomers

Quality Sealing Solutions From Aero Rubber

At Aero Rubber, we pride ourselves on providing the highest quality rubber gaskets and seals in the industry. We manufacture your gaskets and seals to meet even the most detailed specifications. Whether you need a simple gasket or a complex sealing solution, our knowledgeable and experienced engineers and specialists will help you find the best sealing material and design for your needs.

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