Hex keys have a number of important characteristics that make them particularly well suited to the straightforward, user-friendly fastening role that has made them so popular among operators of all experience levels. These include the fact that hex keys:

Long-reach Allen keys are a common feature of most good quality hex key sets, which tend to include a useful range of common wrench sizes and diameters (typically from around 1-1.5mm, up to 12mm and beyond). Our range of long-reach Allen keys are manufactured by leading brands like Irwin, Stanley, Bahco, GearWrench, Wiha Tools, Facom, RS PRO, and of course the original trademark designer, Allen. How would you use a long reach hex key? Allen™ wrenches are available as individual keys of a given size but are also sold in sets that contain a range of standard sizes. Allen™ keys are identified as being either metric-sized keys in millimeter sizes or SAE (Imperial) sized keys in fractions of an inch or decimal equivalents. Besides the common types described earlier, Allen™ wrenches are available with other features that improve safety or increase convenience for using the tool.

Types of Hex Key

A Hex Key is commonly referred to as an Allen Key, this is because Allen was the original manufacturer of the Hex key. Are typically double-ended, thus offering a ‘spare’ hex driver in case of damage or rounding to one end of the tool

Where the additional access provided by a long-reach hex wrench is needed, you'd use the more elongated side as the ‘driver', and the shorter side therefore becomes the handle that you turn to tighten or loosen the fastener. However, when a hex bolt is within easy reach and there's plenty of space to work in, long-arm Allen keys can also be handy used in the reverse configuration - the longer side can help provide better grip and torque when operating as a handle. What types of long reach Allen keys are available? Allen™ screws and wrenches are not the be-all-end-all in the world of fasteners and tools. Some complaints focus on the tool size being too small to allow for one to apply sufficient torque in all cases. Also, inferior materials used in the manufacturing of either the wrench or the screw can render them easy to damage in spite of the increased number of pressure points. But they are still popular more than 100 years after William G. Allen™ filed for his patent and will likely be here to stay for the foreseeable future. Summary T-Shaped Hex Keys: T-shaped hex keys or T bar Allen Keys have a crossbar or T shaped handle at the end which provides a better grip Figure 1 – The cross-section of an Allen™ key showing the measurement for width across flats Types of Allen™ Wrenches Range of access – Allen™ wrenches that feature a hex ball end can allow fasteners to be accessed from angles other than directly in the same plane as the fastener. This can simplify assembly & disassembly in close quarter conditions.In particular, the T-handle design provides a more comfortable grip than the standard L-shaped hex key, but importantly it can also allow for significantly increased torque (provided the gauge of the hex wrench itself is high enough), because the additional weight of the T-handle acts as a counterbalance that can help to seat the tool more firmly and securely in the head of the fastener. This article provided a summary of the commonly available sizes of Allen™ wrenches/keys and explained the different types of Allen™ wrenches as well as the advantages of these tools. For information on other topics, consult our additional guides or visit the Thomas Supplier Discovery Platform where you can locate potential sources of supply for over 70,000 different product and service categories, including suppliers of Allen™ wrenches and other hex key wrenches.