Bob Beecham | posted March 16, 2021 7:39 PM

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Although square and triangular drives appeared about 40 years ago, the hexagonal drive introduced by William G. Allen in 1909 became popular. Today, Allen fasteners can be seen everywhere-from circuit boards to cruise ships. In view of their widespread use, it is not surprising that the Allen wrench itself has many forms. From hand-held models to models for electric drills and impact drivers, the options are very rich.

This guide will introduce the various features and functions that need to be considered when choosing an Allen key. Then, you can check out some of the top products on the market today to help you choose the best Allen wrench for your toolbox.

Whether you are an amateur or a professional, sooner or later you will need a set of Allen wrenches. In fact, almost every household kit used for DIY includes one. When choosing the hex wrench that best suits your needs, the following features need to be considered.

Most wrenches are designed to clamp the outside of hex nuts or bolts. In contrast, an Allen key is installed in a hexagonal groove. This type of wrench is mainly used for mechanical screws and bolts (rather than wood). They can be fitted into threaded (blind) holes or are usually fixed to captive nuts by plates or clamps.

Since the Allen key is installed inside the fixture instead of outside, it is especially useful in confined spaces that cannot be reached by standard wrenches or even sockets. Compared with flat head or Phillips head screw heads, the hexagon socket head fixture also allows greater torque to be applied. This makes the Allen key particularly effective for large fixtures that require a lot of force to secure.

The base material of most hexagon socket wrenches is carbon steel, which has the inherent strength required to handle the torsional pressure (torque) involved in tightening or loosening a series of hexagon socket screws and bolts. Manufacturers can also add nickel or black oxide coatings to prevent rust.

Some Allen wrenches are made of chrome vanadium or chrome molybdenum (commonly called chrome molybdenum) steel. Chrome vanadium steel is very hard and has a certain degree of ductility. It will not crack a little bit, and the chromium element can prevent rust. Chrome molybdenum has similar properties and higher tensile strength (resistance to shear or deformation), which makes it popular in heavy-duty applications.

The basic form of the Allen wrench is either a hexagonal rod or a round rod with a hexagonal end. Then bend it into a common L shape or with a T-shaped handle. On budget tools, the ends of the hexagons remain flat.

There is nothing wrong with this style, but positioning the wrench in the groove of the fixture can be tricky. In addition, frequent use will cause the wrench end or fasteners to wear, thereby exacerbating this situation. The better quality Allen key has a small chamfer. This addition may not seem like much, but it makes a big difference in quickly positioning the wrench.

The ball-end hex key takes this advantage even further. Not only does it help with positioning, it also means that you can apply a certain degree of pressure at an angle, which is very useful when screws or nuts are difficult to access.

The length of a standard Allen key is usually between 1 and 4 inches, so you can hold it comfortably in your hand, usually applying pressure with two or three fingers. Folding hex keys are usually short to be as compact as possible. Although you may lose some leverage, the thick body provides solid support.

T-handle models are usually longer. Twisting these wrenches will produce a huge amount of torque, but it may not be possible to squeeze them into tight spaces. Depending on the application, you may want to purchase more than one set of Allen wrenches. Fortunately, most suits are affordable.

If you have several sets of wrenches in your arsenal, it is often helpful to purchase a separate wrench organizer to provide some structure to your toolbox. Fortunately, most Allen wrench sets include some form of organizer.

Low-cost Allen wrenches are usually like a set of keys on a key ring. Unfortunately, this is not as practical as it seems, and the connecting wires are easily stretched or separated. Plastic clip-on shelves are the most popular choice, usually marked with dimensions for easy identification. T-shaped allen wrenches usually come with their own bracket, which is very suitable for workbench use, but it is too bulky for most toolboxes.

There are two commonly used measurement systems: SAE (Society of Automotive Engineers) is an imperial system, also known as an imperial system, while a metric system is usually used for goods imported from Europe and Asia.

Although equivalents are usually provided, the slight difference in actual fastener size means that SAE and metric Allen wrenches are not interchangeable. Trying to force them will cause damage. Plan to buy the right system for most of your needs, or invest in an Allen wrench set that includes SAE and metric wrenches.

The number of allen wrenches in a set varies greatly. Sets rarely contain less than eight wrenches, and these usually cover common sizes. However, kits that provide both SAE and metric sizes can contain 20 or more wrenches.

Now it's time to apply the knowledge of the above functions to choose an Allen wrench. Read on to discover our recommendations in various categories and add some of the best Allen wrench sets to your toolbox.

The Tekton Allen wrench set is one of the most comprehensive wrench sets on the market; it is a 26-piece set, including 13 SAE tools and 13 metric tools. The classic "L" shape has a small chamfer at one end to aid positioning, while the ball head increases their flexibility. Each wrench in this set has a corrosion-resistant black oxide coating.

Some Allen wrench housings may be very loose. However, the hinged housing of these wrenches can securely hold the tool when not in use, and then open flat for easy access. Each housing unit has a different color and is marked with a separate wrench size for instant identification of the measurement system. Overall, this Allen wrench set is well-made, presented in an easy-to-use way, and very affordable.

Each of this set of 11 metric allen wrenches from Wera has its own color-coded socket, marked with a size, which can be quickly identified and improved hand comfort, especially on cold days. If the print eventually wears out, the size will also be laser engraved on the wrench.

The Hex-Plus design of these wrenches is a unique shape designed to provide better engagement and reduce wear. Multi-layer black laser coating can prevent rust, and has strong resistance to chipping or abrasion. Compared with many competitors' products, this Allen wrench does require a larger investment, but its accuracy and durability are excellent.

This 11-piece SAE Allen Key from Eklind proves that it is possible to achieve quality with the smallest budget. These durable U.S.-made tools are made of heat-treated and tempered steel, which not only provides the hardness required for a long service life, but also provides a certain degree of bending to prevent breakage.

Each wrench is coated with an anti-rust coating and meets the standards of the American Society of Mechanical Engineers (ASME) and the American National Standards Institute (ANSI). The housing is marked with each individual wrench size for quick and easy identification.

These small Allen wrenches are an excellent choice for almost any standard toolkit. They come in a variety of sizes and are suitable for common fasteners on self-assembled furniture, electrical equipment, bicycles, lawn mowers, etc.

Most Allen wrenches are classic L-shaped or T-shaped handles. These Powerbuilt Allen wrenches have a sliding handle that can be operated in any way to maximize grip or torque according to application requirements.

The speed sleeve also allows the user to hold the shaft firmly while still being able to rotate the handle freely for quick tightening or loosening. This expanded range makes the suit a popular choice for car and motorcycle engineers.

These wrenches are made of tough chrome vanadium steel and are one of the best materials for these tools. The eight-piece metric set is installed in a smart, stable rack, which can be placed upright for quick identification and easy selection.

Bondhus uses a proprietary alloy steel called Protanium to make this allen wrench, and then coats its proprietary ProGuard anti-rust coating on each tool for extra flexibility.

The welded T-shaped structure of each wrench is wrapped in a thick cushioned handle, which is ergonomically designed to minimize the pressure on the user's hand. This allows for all-day use with little chance of discomfort or cramps, which may be a problem with less user-friendly tools.

The kit includes 10 SAE Allen wrenches placed in a molded bracket for bench use or wall mounting. Given its heavy-duty nature, the suit provides excellent value.

This Allen wrench from Stanley includes nine SAE tools and eight metric tools, each of which is clearly marked in size and conforms to ANSI specifications. The sturdy composite body has rubber inserts to ensure a firm grip. If the wrench starts to loosen over time, the user only needs to tighten both sides to resume normal action.

The kit is inexpensive and is ideal for adding to a home or professional kit or storing it in an RV or trailer.

Most Allen wrenches are made for hand use, but this means that the amount of torque that can be supported is limited. In the case of heavy industry and engineering, this may not be enough. The solution is a set of Allen wrenches suitable for impact wrenches.

These wrenches from Sunex Tools are equipped with high-performance models of ½-inch drives. The set includes 20 wrenches: 10 SAE tools and 10 metric tools. Each wrench is a solid single piece of chromium molybdenum steel to ensure that it can withstand extreme requirements while complying with ANSI standards.

The size markings are laser etched on each wrench, so they will not wear out. The heavy-duty storage box is easy to transport.

The purpose of this guide is to fully understand the key characteristics to consider when selecting the best Allen wrench for a specific task range. Although it is comprehensive in nature, you may still have some questions. Check out some of the most frequently asked questions about allen wrenches below.

Yes. Strictly speaking, the Allen name is owned by Apex Tools Group, but generally speaking, the terms "hex wrench", "hex wrench", "hex wrench" and "hex wrench" all describe the same type of tool.

The hole in the middle of the Allen key is suitable for tamper-proof hex screws, which are usually designed to prevent unauthorized access to sensitive parts of the device. You can still use this tool as a normal Allen wrench.

All hex wrenches are used in the same way. Insert the hex end of the rod into the relevant screw or bolt, and then turn it to tighten or loosen it. T-handle models generally allow greater force and/or greater range of action. If it is difficult to access, you can use a ball-end hex key at an angle.

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