EngineLabs Tool Of The Month: Summit Racing AN Wrench Kit

Performance automotive plumbing is one of the more specialized things we do as automotive enthusiasts. While for most enthusiast-level projects, the wrench and socket set you get from any of the big retailers will fit the bill, when it comes to AN fittings and braided hose, the tools to work with the fittings and lines are a specialty affair — at least they should be.

Luckily for us, our friends at Summit Racing offer a complete kit (P/N: CSUM2405) of what are called “AN Wrenches” and a set of cutters designed specifically to cut stainless-braided hose. So, today, we’re taking a look at what’s in the kit, along with a brief explanation of why the kit exists in the first place.

AN wrenches offer a host of features tailored specifically to working with aluminum AN fittings. Besides the fact that they are sized exactly for the fittings they are designed for, they are made from the same aluminum, which prevents damage to the fittings. They also have shorter handles to help prevent over-torquing the fittings.

Steel Sharpens Steel, But Gouges Aluminum

We’re going to quickly touch on the basics of AN fittings, to explain why you want specific wrenches. An “AN” fitting is a hose-end fitting that is made of aluminum. While strong and lightweight, aluminum isn’t the hardest metal in the toolbox, which is perfectly acceptable, as long as several precautions are taken. The first is to use a specific AN wrench on your fittings. Because AN wrenches are made from aluminum as well, they are much less prone to gouging the fittings while loosening or tightening them.

A second feature you’ll notice on AN wrenches is that they aren’t particularly long. That’s done in order to limit the amount of mechanical leverage you can apply to the fittings. AN fittings use a 37-degree taper seat to mate, meaning there are no gaskets or sealants required. Unfortunately, that makes the fittings prone to cracking if you apply too much torque when tightening them. By being “stubby” not only do they make it harder to over-torque the fitting, but also allow you to get into potentially tight quarters.

The Summit Racing kit comes with -3, -4, -6, -8, -10, -12, -16, and -20 AN wrenches and a cutting tool designed specifically to cut stainless-steel braided hoses. And, for added convenience, an adjustable AN wrench, which can come in handy when you are working with multiple fitting sizes when time and or space are in limited supply, like at a racetrack. Officially it's adjustable between -3 and -8 AN, but it does open wider, and is handy if you happen to have any oddball fittings that don't conform to the traditional sizing convention.

AN wrenches and fittings also have a unique sizing nomenclature. They are referred to by “dash” size, (i.e -6AN is “dash-six”). The number following the dash is the number of sixteenths-of-an-inch of the nominal tube OD. So, in our -6 AN example, that would be 6/16ths of an inch, or 3/8-inch, OD. The flats of each AN size fitting are nominally the same, so all -6 AN fittings would have the same 11/16-inch distance across the flats of the fittings.

With that understanding, it makes more sense now when we tell you the Summit AN Wrench Kit comes with nine wrenches ranging in size from -3 AN (3/16-inch OD tubing, often found in nitrous applications) all the way up to -20 AN (1-1/4-inch OD tubing, often found in cooling systems), which covers pretty much anything you’ll find in automotive projects. Machined from billet aluminum and color-anodized for wear resistance and easy identification, not only will you be able to securely tighten and loosen any AN fitting you need, you’ll do so without risking damage to the fitting.

A lot of people like to make fun of adjustable wrenches, but in this case, the extreme utility of the adjustable AN wrench design far outweighs any potential downsides.

Cutting Steel Like Butter

AN fittings are attached to specialty hose, the most popular type being braided stainless. Comprised of a tough synthetic rubber core sheathed in a finely braided stainless-steel loom, the hose has impressive strength and flexibility. However, one thing that is tough to deal with, is cutting the hose. There are a multitude of ways that people have cut it in the past, but the simplest way is with a set of cutters designed specifically for the task.

Cutting a stainless braided hose is no easy feat. The Summit Racing cutting tool not only has blades designed specifically for that purpose, but it also has extended handles to allow you to get extra leverage on the cut.

Since cutting through stainless steel is no easy task, the Summit Racing braided-stainless hose cutters feature extended handles for increased leverage on the blades and a pair of crescent-shaped blades that will accommodate hoses up to -12 AN in size. While they might look like garden “loppers” don’t be fooled, the braided-stainless hose cutters are aimed specifically at the singular task of cutting braided hose easily and cleanly.

With the complete kit from Summit Racing, you can get everything you need to properly build AN lines for your project in a single part number, along with a storage roll to keep your wrench set organized whether it’s in your workshop or race trailer.

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Greg Acosta

Greg has spent nineteen years and counting in automotive publishing, with most of his work having a very technical focus. Always interested in how things work, he enjoys sharing his passion for automotive technology with the reader.
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