Allen Wrenches

Allen Wrenches, also called hex keys, Allen keys or hex wrenches, are six-sided L-shaped wrenches designed to drive hexagon-shaped recessed holes. This makes hex keys the tool of choice for socket cap and socket set screws found in mechanical equipment, bicycles, engines, and assemble-it-yourself furniture. Due to most hex keys' looking similar, most find a labeled set to be the most efficient. They are available in SAE (US) and metric sizes.

The term Allen is from a manufacturing company that makes these wrenches. The generic term for an Allen wrench is a hex key.

The short side of a hex wrench is used when more torque is required, and the longer side is used for length. The long side can also be used to fasten socket cap screws in deep recessed holes the short side cannot reach. A benefit of this style of Allen wrench is that the entire tool is shaped as the drive. If one of the ends wears down from use, it can be cut off, and the tool can be used again.

Allen keys have many benefits:

• Simple light tool used everywhere; Most DIY furniture kits have Allen wrenches included and many machines use hex drive screws
• Six contact surfaces, making Allen wrenches less likely to strip or slip than Phillips or slotted drive screws
• Drive recess is internally housed protecting it from harm
• Fits in tight places

Due to the nature of hex keys, they are also the only drive style used with headless screws (set screws). L shaped hex keys are extremely light tools that can fit into very tight spacing. This has made them exceedingly popular on bicycles, motorcycles, and in furniture sets alike. Often furniture manufacturers will make all connections use the same size hex cap screw and include the wrench. Bicycle enthusiasts often carry a set of hex wrenches with them for on the go repairs.

Many varieties of hex wrenches are available, and choosing the right kind will make jobs significantly easier. Albany County Fasteners carries individual Allen Wrenches, Allen Wrench Sets, and T Handle Hex Key Sets. T handle sets are excellent for shops and on equipment where a lot of room is available. They offer a comfortable ergonomic grip to make installation and removal of socket head screws easy while also providing increased fastening power for driving or removing screws.

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Short Arm SAE Hex Key Specifications

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Long Arm SAE Hex Key Specifications

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Short Arm Metric Hex Key Specifications

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Long Arm Metric Hex Key Specifications

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Torx / Star Tamper Proof L Key Specifications

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FAQs

What are Allen Keys used for?

Allen keys, or Allen wrenches, are simple tools used to drive screws and bolts with hexagonal drives or sockets. Socket Cap Products, such as socket set screws and socket cap screws, are predominately driven with Allen keys.

Are hex keys the same as Allen keys or Allen wrenches?

Yes. A hex key is a generic term for this type of tool while "Allen key" and "Allen wrench" refer to the Allen brand that popularized it.

How do I find my hex key size?

Hex key sizes are stamped on the side of the tool for easy identification.

Why are Allen wrenches called Allen wrenches?

The "Allen" name is a registered trademark, originated by the Allen Manufacturing Company. They created the original patent for these wrenches' manufacturing methods and created the first realized product in 1910. The name stuck ever since.

What are the sizes of Allen wrenches?

Allen wrenches are sized based on the diameter of the wrench. They can be in sizes as small as 0.028" to sizes as large as 1" in diameter.

What can I use instead of an Allen wrench?

We know of a few DIY options that exist that you could use in place of a standard Allen wrench hex key. One option is to find a flat head screwdriver that fits tightly across the corners of the hex drive. You could also use a Torx or Star drive bit or screwdriver that fits snuggly in the hex drive to turn it. A hex head bolt could also work if you find one with the right head size. We don't generally recommend these options, but if you don't have a hex key on hand, they can help out in a pinch.

Is Torx better than hex?

In short, yes. At least as far as just drive design goes. It mostly has to do with drive angles, which is how much you have to turn the driver to turn the fastener. Hex drives have a much larger drive angle (60 degrees) than Torx/Star drives (15 degrees), leading to a greater chance of hex drives stripping out. The smaller drive angle on Torx drives form a much tighter tolerance with the Torx driver, better distributing the concentration of force throughout the drive much better than hex drives do.