Technicians have to be able to seal off fluids from one another or risk a massive leak or worse, a chemical reaction. But which to reach for – an O-ring or a gasket? Are the two ever interchangeable?

It’s imperative you know which to reach for in different situations so you can keep your machines running and your clients safe. Unlike other sealing products used in mechanical work, these two cannot be swapped for one another and each serves a unique purpose. 

Here’s a closer look at the differences and uses for each of these important parts.


Made from rubber, polyurethane, or rubber, these sealants help separate different fluids from their environments. The O-ring sits in a groove between two cylinders and forms an air-tight or liquid-tight seal as they compress together.  

These elastomer materials help O-rings stretch and expand when necessary, then revert back to their original shape and size. 

Reach for an O-ring when you need a seal that can handle high-pressure situations. A standard O-ring can withstand up to 1,500 psi while maintaining integrity. This helps them keep gas or liquid from escaping. Use them in dynamic or static applications like fuel seal points, oil or hydraulic seals, fuel systems, or pipe joints. 


Made from different materials like silicone, nitrile, Viton, or neoprene, gaskets are much more versatile than O-rings. They can be layered with different coatings for different jobs or uses, and come in a variety of shapes. If you need one, you can custom order a gasket for two mating surfaces to make sure they hold together perfectly.

While an O-ring is always a circle, a gasket can be a triangle coated in pressure-sensitive adhesives or even laminated as needed. When a system is disassembled and then put back together, it’s always a good idea to replace the gaskets. 

These versatile parts help different manufacturers make paper, generate electricity, and pump oil and gas.

When to use a gasket or an O-ring

  • Groove – use an O-ring
  • Flat surface – reach for a gasket
  • Extreme temperatures – choose a gasket
  • High pressure – always pick the O-ring

Key Takeaways

  1. O-rings are only produced as circles, while gaskets can be customized for any shape, size, or coating depending on how you plan to use them.
  2. Gaskets work best on flat surfaces, while O-rings require a groove for a proper fit.
  3. High temperatures require a gasket, while high pressure calls for an O-ring.

Want more help finding the right parts for you, your business, and your work? Please don’t hesitate to contact us. Our passionate, professional staff at Cannon Gasket is always happy to help.