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Chances are that when you’re selecting air fittings for your compressed air system, you’re likely to need to decide between using industrial or automotive fittings, as these are the two most common.

A lot of people find it difficult to know which is more suitable for their system, and so, this article will provide all the relevant information on the two so that you’re able to select the right one for you!

Table of Contents

What are Automotive and Industrial Air Fittings?

First of all, let’s clarify that automotive and industrial air fittings are “styles” of air fittings that differ from one another. When selecting air fittings, one of the most important considerations is first of choosing the style that fits your system, before then proceeding to select the right size.

It’s very common for people to ask which style is better? Well, there is no difference in performance or longevity between the styles. It is just a matter of preference or a matter of what style is already installed in your system. The most important factor to understand is that the two styles are not compatible with one another.

Choosing the Right Air Fitting

Given that there are two common styles of quick-connect fittings – automotive and industrial style. The most common difficulty for people is when they have existing air fittings installed in their system and they purchase the wrong style. If you already have air fittings you want to make sure you purchase the same style as your existing fittings so that they fit together.

If you don’t know what style you have, my advice is to check the tip of the male plug. The female coupler, unfortunately, will give you no clue on what style it is. Here are some tips to help you distinguish between an automotive and industrial air fitting:

Automotive Style Air Fitting

The automotive-style male plug has a beveled inward tip, which kind of looks like a spark plug hence the name, automotive. Automotive-style couplers tend to have one stripe going across the fitting.

Here is an example of automotive-style air fittings readily available on Amazon!

Industrial Style Air Fitting

The industrial-style male plug has a bevel or ring protruding outward on its tip. Industrial-style couplers generally have two stripes going across the fitting.

Here is an example of industrial-style air fittings readily available on Amazon!

Each of the different styles of plugs has a matching coupler. If you have that specific coupler, chances are it will only accept a plug with the same style. Although it is said that some industrial-style couplers will accept V-style plugs, I wouldn’t bank on it.

The problem is most of the couplers look the same on the outside, so they are far harder to identify than plugs. There is a supposedly accepted way of identifying them via counting the number of thin and thick “stripes” on the body of the coupler as described in the tips above, but it’s pretty useless because not everybody adheres to it.

Also, another thing to consider is that unless you have two couplers from a single manufacturer, one company’s thick stripe can look like another company’s thin stripe which can make it difficult to distinguish. Plus you have to remember which marking is in which style, and then of course the plugs don’t have matching markings.

Some manufacturers, if you’re lucky, will stamp their disconnect fittings with the product number. Usually, in the product number, there will be an I for industrial style or an A for automotive style. However, the industrial plug is sometimes referred to as the M-style, while the automotive is listed as the T-style or C-type.

There is also a V-style, which is meant for high flow compressor air distribution systems. It is similar to the industrial, except that the plug is wider to accommodate greater volumes of fluids.

Some contractors who operate multiple crews will use different color air hoses and different styles of fitting for each crew. This way they don’t “borrow” each other’s air hose. Aside from these two common types of fittings, there are some universal fittings that will work with either style, but the majority use a single style fitting.

FAQs (Frequently Asked Questions)

Are industrial or auto air fittings better?

There is generally no difference in performance or longevity between industrial-style and automotive-style air fittings. It is simply a matter of preference. It’s advised to purchase whichever already exists in your compressed air system so you’re able to install the new fittings.

Are industrial and automotive air fittings interchangeable?

No, you must ensure that if you have industrial or automotive air fittings already installed in your air system you purchase the same one to be able to fit them together. These fittings will not fit into one another, and one of the most common mistakes compressed air users make is purchasing the wrong fitting.

Additional Reading:


If you have any questions regarding industrial vs automotive air fittings, please leave a comment below, with a photo if applicable, so that someone can help you!