What Is an Allen Wrench? All About the Must-Have Tool for IKEA Furniture
I’ve been buying IKEA furniture for nearly 20 years, and I’ve put together a lot of flat-pack furniture in that time: a HEMNES dresser, a BEKVAM kitchen cart, at least three RAST chests, and so much more. Needless to say, I’ve amassed quite a collection of freebie Allen wrenches.
You probably have at least one Allen wrench from a flat-pack furniture box, too — or if not, you’ve used and tossed one in the past. But have you ever wondered who Allen is and why his wrenches are so popular for DIY-assembly furniture?
An Allen wrench is, like Kleenex or Xerox, actually just a brand name for what is more generally known as a hex key: an L-shaped metal bar with a hexagon-shaped head. And there’s actually a pretty good reason why you’ll find this in almost every flat-pack furniture box. Here’s everything you need to know about what an Allen wrench is and what it’s good for.
Allen Wrench Basics
An Allen wrench (also called an Allen key) is just a brand name for what is more generally called a hex key. This is an L-shaped bar that has a hexagonal shape that fits into screws with hex-shaped socket heads.
Hex keys are popular for flat-pack furniture because they’re cheap and easy to produce, and you’re much less likely to strip the screws.
What is an Allen wrench?
The Allen wrench is an L-shaped bar that has a hexagonal profile and two blunt ends. There is one long arm and one short arm, both of which can be used to turn Allen screws.
Like other types of wrenches, the Allen wrench is used to apply torque to turn bolts, nuts, or screws. Unlike other common wrenches, the Allen wrench doesn’t fit around the outside of the screwhead. Instead, the corresponding screw is fitted with a socket that matches the hexagonal shape of the wrench. To drive the screw, you insert one end of the Allen wrench into the socket and turn it.
How did the Allen wrench get its name?
It turns out Allen was a real guy: William G. Allen, owner of the Allen Manufacturing Company, wasn’t the first to make a screw with a hexagon-shaped socket (and the corresponding tool used to fasten it), but he was the first to patent it in 1909. Allen Manufacturing Company started manufacturing hex keys the following year. (Allen Manufacturing Company no longer exists; it later transformed into Apex Tool Group.)
The Allen wrench, or Allen key, was the name of the hex key that Allen Manufacturing Company designed and sold, and it’s taken hold as a common name for the tool more broadly.
How to Use an Allen Wrench
Having two arms of unequal length isn’t a design flaw — it’s what makes the Allen wrench usable in a variety of situations.
To get more torque, or force from twisting the wrench, insert the short arm into the screw and use the long arm to turn. That gives you more leverage and makes faster work of fastening the screws.
To fit into tight spaces, insert the long arm into the screwhead and twist the short arm. It won’t be as quick or as easy as using the long arm to turn the screws, but it will allow you to squeeze into spaces that can’t accommodate the long arm.
Why are Allen wrenches used for IKEA furniture?
Allen wrenches are used for a number of different types of flat-pack furniture, but they’re most iconically associated with IKEA products.
The reason Allen wrenches are such a good match for flat-pack furniture is that the tools themselves are easy and cheap to manufacture, so the exact size needed can be included with every box. And since you have the exact right fit for the socket cap screws included with the piece, you don’t run the risk of stripping the screws (something that can happen with other types of screws if you don’t use a correctly sized screwdriver).
Should you buy a set of Allen wrenches?
Even though Allen wrenches come with every product you’d conceivably need them for (aka seemingly every flat-pack piece of furniture), it’s still worth having a set of your own on hand so that you can take apart your furniture for a move, tighten loosened screws, adjust heights of legs, and more.
I don’t think you need anything fancy here; I have a really basic set of Allen wrenches labeled by size that all fit neatly into a little plastic pouch, similar to this one. This is a product that you don’t need to splurge on — a perfectly serviceable set will run you $10 to $15.
Another option here is to keep all of your old Allen keys from various packages together, and label them by size or with the name of the product you used them for. That has the advantage of being free (a real perk!) but can feel a little less organized and tidy.
Can you use Allen wrenches with a drill?
Allen keys aren’t the only tools that you can use to turn socket head screws. If you want a little more force behind your fastening, you can use hex-shaped bits paired with an electric screwdriver or a drill.
When using a drill, be careful not to overtighten the fasteners, which can damage the item you’re putting together. Keep your drill to the lowest setting and work slowly.