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How to Use an Allen Wrench

Collage photo of allen wrenches.

If you have ever purchased some assemble from home furniture or perhaps worked on a motorized vehicle yourself or worked on a bicycle, you will notice a screw or bolt with a hexagonal head that requires an Allen wrench.

Sometimes, you may have seen a small L-shaped wrench in that last purchase you assembled at home. Allen wrenches, or hex keys, are a standard tool used a lot in around-the-house projects.

Because it is such a common tool, it is essential to understand the proper way to use an Allen wrench.

What is an Allen Wrench?

This is a look at various hex key pieces on a wooden table.

Before we elaborate on using the tool, it is vital to ensure we speak first on what it is and what that tool does. Like the screwdriver, an Allen wrench is a simple tool by design. Generally, they come as a set of different-sized L-shaped pieces of metal.

However, just because they are simply designed does not mean they are useless or unimportant tools. Users will be astounded by the utility and universality of the Allen wrench.

Allen wrenches most often are used to tighten or loosen Allen screws or bolts. This is most commonly done on bicycles or furniture. However, it seems that more industries are using Allen wrenches.

Allen wrenches most commonly come in the L-shaped wrench. However, there are different types of hex keys. Another form the Allen wrench is frequently seen in is the T handle wrench. This type of Allen wrench creates a T shape where the hex-headed wrench goes down from a T-shaped handle.

These are designed for easier turning. Another common form of Allen wrench is the fold-up sets. The fold-up set is akin to a pocket knife, where the Allen wrench hex heads all fold up into a base.

Regardless of the design of your hex keys, it is essential to know the proper way to use an Allen wrench. Many of the designs have different pros and cons. However, the application of the tools does not vary much between the wrenches.

Mechanics of Using an Allen Wrench

This is a close look at someone assembling a furniture with an allen wrench.

Using the traditional L-shaped Allen wrench, the user puts one of the two ends into the hex-headed screw or bolt and turns the wrench clockwise to tighten and counterclockwise to loosen. The L-shaped wrench does have the advantage of providing leverage for a lot of torque.

If needed, inserting the short arm of the L into the hex head will allow users to manipulate a lot of leverage and torque on the long arm of the L-shaped wrench. This can be especially beneficial for loosening very tight screws. The longer end of the wrench can be used for hard-to-reach places as well.

The T-shaped Allen wrench also carries the advantage of being able to reach tight spaces. The T shape design also allows for ease of turning the screw in a more traditional screwdriver-type motion.

Using the T-shaped Allen wrench simply requires inserting the hex key into the hex-headed bolt and turning right or left, depending on whether your want to tighten or loosen. The T-shaped Allen wrench cannot generate quite as much torque as the L shape.

Allen wrench fold-up sets are similar to the T-shaped Allen wrenches, except they have the handle of the fold-up set to use as the method of turning the wrench. This is great because it can be adapted in a couple of different ways.

The folding hex wrench can be used almost identically as the T-shaped Allen wrench, with the wrench halfway folded up and the handle acting like the cross-section to turn.

However, when the wrench is turned in the upright position, like a pocketknife, it is akin to a screwdriver. This tool is used as the other hex head variations by inserting the hex key into the hex headed screw and turning either clockwise or counterclockwise.

Consumers can also find a hex fastener designed to fit in a screwdriver with replaceable heads, designed for a torque wrench, and even intended to be used with a drill. These are generally adapters that will fit onto a more familiar tool instead of buying a set of traditional Allen wrenches.

These can be a terrific option for those not comfortable with the different shapes of the Allen wrench.

Purchasing Allen Wrench Sets

This is a set of stainless steel set of allen wrenches with a green holder.

Allen wrenches can be purchased individually or in sets. I recommend buying them in a set to have all of the different sizes in case the need arises. I also recommend purchasing both a standard American set as well as the metric size.

There is a lot of variation regarding the types of projects that require an Allen wrench and whether or not those projects will have American or metric wrenches. Allen wrenches are not extremely expensive tools, and it is convenient to have a complete set of both.

Often, when you buy furniture or other projects to assemble at home, an individual wrench is provided in the materials. Still, single Allen wrenches are hard to keep track of, and it is good sense to keep a complete set of wrenches on hand if you need them.

There are a lot of different options for purchasing a hex key set. Individuals should find their preference, whether L-shaped, fold-up sets, or T-shaped wrenches. Hex heads can also be purchased to fit a drill, sockets, or screwdriver heads. Another convenient way that sets can be purchased is on a key ring.

This allows for all the different styles to be in one convenient place different than others. The style is less important than having an American and metric set that you can conveniently access when needed.

Another factor to consider when purchasing a set of Allen wrenches is how many to have in each set. Hex keys vary in size; however, some are not as used as others. Some of the larger sizes are only used in cars, trucks, or other heavy machinery. For casual, everyday use to have in your home, you should be ok to have roughly eight to twelve metric wrenches and eight to twelve American wrenches.

However, if you regularly work on large machines or big rigs, purchasing larger metric and American sets could be beneficial. It is essential to consider your needs for the tools and understand how many you may need before buying your Allen wrench set.

When to Use an Allen Wrench

This is a close look at a mechanic repairing a motorcycle with an allen wrench.

As you work around your home and possessions, you will be surprised how often the occasion for an Allen wrench will be needed. Whether it is building, repairing, or dissembling furniture, working on your car or motorcycle, or working on a household appliance, you will see the wisdom in having a complete set of hex key wrenches and knowing how to use them properly.

There are other uses for the Allen wrench other than the traditional method of use. Often, the smallest Allen wrenches can be used to help pick a lock for individuals who are locked out of their houses. Often, many power tools require Allen wrenches for repairs.

This is especially common for chain saws, drills, and other saws. Allen wrenches are also being used more frequently in the electronic industry. It is now more common than ever for Allen screws on phones, tablets, and computers.