The idea of a hex socket screw drive was probably conceived as early as the 1860s to the 1890s, but such screws were … See more

Some features of hex keys are:
• The tool is simple, small and light.
• The contact surfaces of the screw or bolt are protected from external damage.
• There are six contact surfaces between bolt and driver.… See more

The term "hex key" is best known as "Allen" in the English-speaking countries like the UK, Australia, Canada and the U.S. (The "Allen" name is a registered trademark, originated by the Allen Manufacturing Company o… See more

Hex keys are measured across-flats (AF), which is the distance between two opposite (parallel) sides of the hexagon.
Standard metric sizes are defined in ISO 2936:2014 "Assembly tools for screws and nuts—Hex… See more

Hex socket screw heads are usually made by stamping the head with a die, plastically deforming the metal. Other ways to generate the hex socket include linear broaching and rotary broaching. Broaching the heads … See more

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• List of screw drives See more