A User's Guide to Common Allen Wrench Sizes A User's Guide to Common Allen Wrench Sizes

An Allen wrench is one of the most popular and common tools in the average do-it-yourselfer’s toolbox. This wrench, identifiable by it L-shaped head, can be used for a variety of purposes, but mainly it’s used in automotive repair, for unclogging sink garbage disposals, and for putting together pre-fabricated furniture. Allen wrenches are often quite small, and come in several standard sizes as determined by the SAE International, including 5/32-inch, 3/32-inch, 7/16-inch, 3/16-inch, 1/18-inch and ¼-inch sizes. Which size is best for a particular job? Keep reading this handy user’s guide to common Allen wrench sizes to find out.

Metric Sizes or Standard Sizes?

One thing to keep an eye on in terms of sizes if you’re looking to buy a set of Allen wrenches is whether the sizes are in standard measurements (as given above), or in Metric. The type of size you should get depends on what kind of work you intend on doing with the wrenches. For instance, if you’re going to be using the Allen wrench to work on your car, there’s a good chance that you may be required to use the Metric measurement wrenches, if the car is of a foreign make. The same is true of many types of bikes.

On the other hand, if you just want some Allen wrenches for light repairs around the home or for furniture assembly, the Standard measurement wrenches might be your best bet. Fortunately, Allen wrenches are some of the less expensive tools out there, so you might be best off owning both types.

Common Sizes of Allen Wrenches

Although Allen wrenches come in a wide range of sizes, there are a few sizes in particular that tend to be more commonly used than others. In standard measurements, the most common Allen wrench sizes for the tasks listed above (that is, automotive repair, bike work and furniture assembly) are the 5/32-inch, 3/16-inch and ¼-inch sizes. Therefore, even if you don’t want to buy a hole set of Allen wrenches, it’s still a good idea to have at least these sized wrenches in your tool kit.

What About the Other Sizes?

So if those are the most common sizes of Allen wrenches, then what about the other sizes, right? Why are there so many to choose from? The smallest sized Allen wrenches are most commonly used for things like electronic repair, which often are built using very tiny fasteners that screwdrivers and other tools can’t remove, and which have to be repaired with small, delicate instruments. Car repair may also require a greater range of sizes, depending on the make of the car and the type of repair that’s being done. Therefore, the full range of Allen wrench sizes is most useful for the handyman or do-it-yourselfer who is involved in more involved, extended repair projects.

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