Hex Keys: A Complete Guide

Claudette B.
Jan 18, 2023
3 min read

Hex keys. You've probably seen them when putting together flat-packed furniture or in your hand tool kit. They're sometimes called Allen wrenches or Allen keys thanks to a Connecticut-based manufacturing company, Allen, who released their version of the hex key in the early 1990s.

But what are they? To be precise, they are small metal tools with six points of contact (hence the word, 'hex') that are used to install and remove hexagonal-shaped bolts and screws. They often take an 'L' shape, although there are different variations of the tool available on the market.

These days, these tools are so standard that you'll find them in those little bit/tool packets when you buy furniture. These hex keys, however, will only feature sizes convenient for assembling that specific piece of furniture, so you'll usually only find one in there. A good tradesperson will have a hex key set handy, since these come in myriad sizes and are often much better in quality.

Want to know more about these commonplace yet highly efficient tools? Look no further than below, where we offer you a comprehensive guide on all things hex keys; from understanding the basics and choosing the right set for your needs to proper maintenance tips.

Understanding the Basics of Hex Keys

Hex keys are a cost-effective option when it comes to tightening or loosening a hex screw. They work by gripping securely onto the screw, making it easy to get the right amount of torque for your tasks.

They also fit into tight spaces, so are ideal for moments where your impact wrench doesn't quite reach a corner.

Sets of hex keys often come in sizes 1.5-10mm, meaning screw heads are not a one-size fits all. This is why you'll find a variety of sizes in your toolkit.

The most common hex key – i.e. the one that usually comes to mind – is the steel, flat end L-shaped tool, since these are so widely used in both household and professional settings. However, did you know you can also get multi-coloured L-shaped hex keys, ball end hex keys, T-shaped hex keys, as well as folding hex keys and straight hex keys? Well, now you do! And here at UK Planet Tools, you can take your pick, since we've got so many options in store.

Choosing the Right Set of Hex Keys

When choosing hex keys, it's important to consider the size and shape of the bolts and screws you will be working with. That's why a set is such a good option, since it will provide the most commonly used sizes at your discretion.

What's more, it's also an idea to choose an Allen key set that is constructed of durable materials, e.g. steel or chrome-vanadium, as these materials are known for their strength and corrosion resistance.

Another consideration when choosing a set of hex keys is the handle. Some hex keys come with a T-handle or a ball-end handle, which can provide a better grip and more leverage when tightening or loosening bolts. Flat ends are often the standard when it comes to those free hex keys that come with your furniture that we talked about, but since the quality of those tools are more DIY than professional, we recommend you choose from a T-handle or ball end for the best results.

T-handle hex keys

With such a comfortable grip, it's no wonder that the T-handle hex key is such a staple tool in mechanical and automotive work. However, you don't need to be a mechanic to understand the benefits of these hex key types. Just use one for yourself and you'll feel how something as simple as an added handle significantly increases torque.

TRK offers a great 10-piece set for those looking for quality T-handle hex keys:

Durable materials: These TRX T-handle hex keys are made of chrome vandium double-ended steel with moulded plastic t-handles to withstand tough environments
Convenient T-handles: T-handles are great for mechanical work as the weight of the handle works as a counterbalance to secure the tool in screws, improving torque
Comfortable grip: The plastic handles are comfortable to use over long periods, meaning the user can complete tasks with little wrist strain for a faster performance

Ball end hex keys

A popular choice among household users, mechanics, handypersons and other professionals is the ball end hex key (or as it is sometimes referred to, the ball head hex wrench). These are the Allen keys you'll usually find in a toolbox or set, which'll give you easy access to cramped spaces. With durable steel bodies, they'll last for years to come, too.

This Milwaukee ball end hex key set is a hit you can't miss:

Twist and lock case: For easy access to hex keys, this Milwaukee Allen key set is fitted with a locking system that simply twists to unlock
Ball end: For up to 30° access to screw heads, this hex key set from Milwaukee has ball ends that also work to increase torque and access tight corners
Size identification: Clear size labelling helps to easily identify the hex keys (9 pieces included in sizes 1.5, 2, 2.5, 3, 4, 5, 6, 8, and 10mm)

Proper Maintenance of Hex Keys

To ensure that your hex keys last for a long time, it's important to take good care of them. Proper storage and cleaning are key (no pun intended).

You should store hex keys in a dry, cool place (like a toolbox) and avoid exposing them to moisture and humidity. It's also a good idea to clean them regularly to remove any dirt or debris that may have accumulated on the keys. For the easiest maintenance, opt for rust-resistant steel.

For hex keys that won't rust, try TOUGH MASTER®:

Bright colour & textured surface: The hex keys are in bright colours which vary depending on size to make it easy to distinguish which one is which
Premium materials: The heavy duty allen keys are made from the finest CR-V 6150 steel and have special surface tempering and finishing for a premium set
Ergonomic design: The spherical ball head design makes this hex long key set extremely versatile as it can be tilted in a 25-degree narrow space to allow access to corners

Working with hex keys

Now that you understand the differences between hex keys and how to make them last, you'll be able to use them correctly on the jobsite or at home doing various projects.

Tip: Always be sure to have a set of hex keys in your toolbox, as they are handy tools that you'll use more often than you think.

Or better yet, keep a set of each type, so you can pick which one you want to use depending on your task.

On that note, let's get to work!