What's the Difference Between 37 and 45 Degree Flares?

What’s the Difference Between 37 and 45 Degree Flares?

August 12, 2022

When working with tubing or pipe, you may need to create flares on the ends of the tubes. Flares help keep the tubing or pipe from coming loose and make it easier to attach fittings or connectors. There are two main types of flares: 37-degree flares and 45-degree flares. This blog post will discuss the differences between these two types of flares and help you decide which one is right for your project.

37 Degree Flares

37-degree flares are the most common type of flare. They’re used in a wide variety of applications, and they are relatively easy to create. To create a 37-degree flare, you will need a special tool called a flaring tool. This tool has a cone-shaped tip that is inserted into the end of the tubing or pipe. The flaring tool is then rotated around the tube, creating a flare about 37 degrees.

Benefits of 37 Degree Flares

  • They provide a tight seal that helps to prevent leaks.
  • They are less likely to loosen over time and become damaged.
  • The flared connection is stronger than other types of connections, making it ideal for high-pressure applications.
  • 37-degree flares are less likely to crack or break under stress.
  • They are less likely to corrode or become damaged by chemicals.

45 Degree Flares

45-degree flares are less common than 37-degree flares, but they do have some advantages. One advantage of 45-degree flares is that they provide a better seal against the fitting or connector. Another advantage of 45-degree flares is that they are less likely to come loose. This is because the flare creates a stronger connection between the tubing or pipe and the fitting or connector.

Benefits of 45 Degree Flares

  • The tight seal of a 45-degree flare creates a stronger connection and is less likely to leak over time.
  • Easier to install in hard-to-reach places.
  • The tighter seal of the 45-degree flare means it is better able to withstand vibrations and movement.

45 vs 37 Degree Flare Fittings

A 37-degree flare has a smaller sealing area than a 45-degree flare, so it requires less force to make a seal. This makes it ideal for use in high-pressure systems. A 45-degree flare has a larger sealing area, so it can handle more pressure. However, it requires more force to make a seal, so it is not as commonly used in high-pressure applications.

So which one should you use? It depends on the application. If you need a fitting that can handle a lot of pressure, go with a 45-degree flare. If you need a fitting that is easy to seal, go with a 37-degree flare.


When it comes to a 37 or 45 degree flare, it all comes down to the application. Whichever you choose, make sure you get the right size for your application. Contact Royal Brass Incorporated for all of your hydraulic fitting needs. We’ll be happy to help you choose the right flare for your application.

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