A Guide to An Fittings

On the outside, a race car looks smooth and polished. But when you open up the engine, you would see that it has a lot of pipes and plumbing that hooks up one part of the engine to another. How do you ensure that the fluids flow to where they are supposed to be? That is the job of AN fittings – to connect the hoses to the metal tubing that has liquid in them.

Common Types of Fittings Connections

Initially used in the military and aviation industry in World War II, they were made to offer an alternative solution to unyielding tubes and hoses. At that time, they had different hose size specifications because they needed a more durable tubing system. Since both the Army and Navy agreed to the sizes, they decided to name them as AN fittings. But even though the name seems so simple, it comes in various sizes, so it is sometimes confusing. And unfortunately, hose failure is a real and present danger that could be traced to incorrect fitting. It then begs the question – what is the best one to use for your pipes?

What are the Common Types of Fittings Connections?

Not all cars are created equal, and that saying holds for race cars as well. There are three common types of AN fittings in racing.

Crimp type:

The crimp types are usually the most expensive of the three because of the dies and machines. It also requires the use of a new collar, so you cannot reuse them even if you wanted to. Small race teams and individual cars rarely use them. But in reality, these last a long time. They are the most reliable ones when it comes to fittings. It needs a hydraulic press to tuck in the pipe part into the hose’s end, so the tube is just right.

Reusable hose ends:

The second kind would be the reusable hose ends. As the name suggests, you can use it again, so it is more economical than the crimp type. This two-part system is the preferred fitting of a small race team or a mechanic because it can be attached using regular hand tools. A nylon or stainless-steel braided hose goes well with this type. The ones who use this claim that this is clamped more securely than push locks.

Push-lock type:

Of the three, the push lock comes as a single fitting. Just like the reusable ones, you can hook it up using your usual car tools. A braided hose will not work well with this kind because the barb at the end is designed to hold a coated tube in place specifically.

What Sizes are Used on Race Cars? 

Sizing is all about the diameter on the hose. The outer diameter (OD) is in 1/16 of an inch in increments. If you use a -3 size, you will need a hose diameter of 3/16 of an inch. Or if you must use a -12, your OD would be 12/16 or ¾ inch.

You use a -3 size for your brake lines. Fuel hoses will need a -4 or a -6. Your coolant hose will go well with a -6, -8, -10, or -12. And vent hoses can range from a -10 to -12.

The proper fittings are essential for a smooth ride. It is best to be familiar with your car so that you have an idea of what to get if you need to replace your fittings.


Author Bio: Julian Carter is a farmer of words in the field of creativity. She is an experienced independent content writer with a demonstrated history of working in the writing and editing industry.  She is a multi-niche content chef who loves cooking new things.

Leave a Reply