Bubble Flare vs Double Flare

The internal systems of a car may seem quite complex to the vehicle owners. It is quite right. However, it will become quite easy and simple once you split the components into their smallest parts. The same thing is applied for brake flares as well.

One of the major parts of a brake is its flare. This part is responsible for keeping the functions of the brake working properly. Sometimes you may notice fluid leaking from the brake flare. This happens due to the type and quality of the flare used in the brake.

If you want to personally conduct the activity of flaring a brake line of your own car, you must know about bubble flare vs double flare.

Bubble Flare vs Double Flare: The Fundamental Differences

An expert will use both double and bubble brake line flaring tool in your car. Therefore, it is important to know everything about them. Double flare vs bubble flare is a debate that will go in your head as long as your braking system needs a flare.

Let us first look at how the braking system works.

When you push on a brake pedal, the depressing causes compression. This compression occurs in the master cylinder. It creates hydraulic pressure that causes fluid to spread to every area of the car. Eventually, the brake system starts working.

The system’s main criteria to work this way is that there cannot be any air inside. This means that the inside must be airtight. This is exactly where the flare is used. The two most common flare types are the double flare brake line and the bubble flare brake line.

The Double Flare Brake Line

The automotive braking system uses two distinctive types of flares. Between them, the double flare is the most widely used flare across the planet. Despite being so popular, the Europeans mostly use the bubble flare system in their cars.

Apart from the conventional name, double flare is also known as SAE and Inverted Style Flare. Many experts all over the world use these names alongside double flare. The double flares have the capacity to handle different variations of productions.

The double flare system inserts the end line inside the braking system of the vehicle twice. While doing that, the double flare requires the single flare’s lip so that it stays folded over the system. The single flare is another type of flare that looks almost as same as the double flare.

However, double flare is more durable and sturdier. Moreover, there can be heavy pressure occurring inside of a braking system. The single flare cannot handle that. A double flare is very much capable of handling high pressure.

The Bubble Flare Brake Line

On the other hand, a bubble flare is widely popular in Europe. Particularly, the vehicles imported from Europe to other parts of the world, bubble flares are widely used in those cars. Along with that, some vehicles in Asia and America also use bubble flares. It is also known as DIN or ISO.

If someone wants to create a double flare, it must create a bubble flare braking line before that. The outlook of a bubble flare is more like the head of a screw. At the bottom of the bubble flare, there is a 90 degrees flare.

The bubble flare brake lines are the first step in producing the double flare brake lines. This suggests that you will have to go through creating a bubble flare before using the double flare in the braking system of your car.

On the other hand, it is also possible to create a bubble flare from a double flare. Bubble flare is not capable of handling high pressure like a double flare. Therefore, double flares are always preferred. Nevertheless, a bubble flare is usable when the end of the tubing of the braking system resembles a button.

Temperatures of Each Brake Flare Lines

Any flare lines will function under two different temperatures. One is 37 degrees, and another is 45 degrees.

The most popularly used temperature for a flare is 45 degrees. As you already know, double flare is the most common brake flare line. Therefore, the double flare is the one that uses 45 degrees temperature to function. As a result, double flare is sometimes known as a 45-degree flaring system as well.

On the other hand, the 37-degree temperature is often used for the bubble flare. The US Army and Navy (AN) fittings usually use the bubble flare brake lines. The JIC (Joint Industry Council) also uses the 37-degree temperature as the base for fitting.

Making a Bubble Flare with a Double Flare Tool

A double flare is known as an all-in-one toolkit for your braking system. Therefore, it is possible to create a bubble flare from a double flare using the tools. In fact, you can easily make any flare from a double flare.

Having an all-in-one flare for the braking system of your car can be extremely useful. You can easily shift from one flare tool to another. Moreover, it gives you the flexibility and options in your hand.

Future Prospects of the Two Brake Flares

In recent times, the bubble flare has gotten quite popular due to its simplicity. On the other hand, the double flare has more functions than a bubble flare.

Even though the market is shifting, and the bubble flare production is on the increase, the double flare is expected to dominate the market in the near future. The double flare braking system has much more functionalities.

In addition, double flares are widespread all over the earth. As a result, a larger market capture will still belong to the double flare. Nevertheless, production and use of the bubble flare will surely keep on rising.


Knowing the basic differences between bubble flare vs double flare is very important as a car owner. The flare is one of the key components of the braking system of a vehicle.

Again, the braking system of a vehicle is possibly the most significant part of your car. Therefore, having a thorough knowledge of the flaring systems will surely guide you in taking care of your car all on your own.

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