What is the difference between an Allen wrench and a hex key?

Introduction

Have you ever assembled furniture? Or maybe you spend hours in your garage? Then you definitely used this tool. Some call it a hex key, others - an Allen wrench.

For more than a century, people have been using these instruments, they are affordable and popular among many users the world over, including professional mechanics as well as those who need these tools for home use.

Nowadays, there are many hand tools to choose from. But this article is aimed to help you figure out the difference between an Allen wrench and a hex key.

difference between an Allen wrench and a hex key

The short answer is "there is no difference". These two names can be used interchangeably. Let’s figure out why.

When it comes to Allen wrenches (or hex keys), people have questions. We answered some of them.

Why are they called "hex keys"?

hex keys

These instruments are essentially L-shaped wrenches with 6 sides. They are used to drive hexagon-shaped recessed holes. Greek "hex" means "six". Hence the name.

Why are they referred to as "Allen wrenches"?

At the beginning of the 20th century, William G. Allen patented a cold drawing process for making hex socket set screws. Wrenches for turning such screws became widely popular. "Allen" is a registered trademark, however, even wrenches by other manufacturers are sometimes called Allen wrenches.

Allen wrench vs key

You can use the terms "Allen wrench" & "Allen key" interchangeably.

Is a hex key an Allen wrench? Is an Allen wrench a hex key?

Yes. These are the same tools.

Is a hex bit the same as an Allen wrench?

A hex bit is a hexagon-shaped bit that is designed to fit into a manual or power screwdriver or drill.

Is a hex bit the same as an Allen wrench?

Allen wrench

An Allen wrench, in its turn, is a separate manual tool. However, both a hex bit and an Allen wrench have the same hexagon shape (if to look at the front side).

Ball end hex key vs regular hex key

In the world of hex keys there are different types. There are hex keys with a straight end:

Ball end hex key vs regular hex key

and hex keys with a ball end:

Ball end hex key vs regular hex key

Let’s figure out what each type is used for.

Hex keys with a ball end have one undeniable benefit - they are perfect for hard-to reach places, or, for example, if the bolt is located close to the obstruction on one of the sides. In this case, using a ball end hex key is more effective than using a regular hex key. With a ball-shaped end, it is easier to slide your key into the receiving slot. You will save your time, that’s for sure!

With a ball end hex key, the fastener access angle can be varied, there is no need to approach the fastener directly at a 90° angle, which is very convenient.

However, using a ball end hex key is not the best option when it comes to high-torque applications as you will lose some fastener engagement.

It is important to mention that a hex key with a ball end makes point contact with the screw. A hex key with a straight end, in its turn, makes the line contact. Keep that in mind.

Hex screwdriver vs Allen key

The tips of a hex screwdriver and an Allen key are the same but the difference lies in the shapes of these tools. Typically, an Allen key is L-shaped and a screwdriver is straight with a handle for more convenience.

Advantages of hex keys

Allen wrenches are compact, portable, and lightweight, you can take them with you wherever you need to go. In addition, using them reduces fatigue, increasing your productivity.

Many products come with hex keys included, for example, bicycles, furniture, exercise equipment, etc.

Allen wrenches are easy to use, just get the right tool for your specific application.

Final Thoughts

So, Allen vs hex head? Now you know there’s no difference. On Mega Depot, you can find hex keys that come in an array of sizes (measured by across-flats - the distance between the opposite ends of the flat side). Note that if your Allen wrench is bigger than it should be, the fastener or instrument may be damaged.

On our website, there are tools made by various manufacturers, choose the best Allen wrenches that meet your needs. It is possible to buy hex keys separately or in sets.