There are five fast facts about hex keys. The first one, they have to use six points of contact or it's not a hex key. Hex keys are also commonly known as allen wrenchs, even though that name is trademarked. Hex keys have been around since the 1800's. One of the reasons hex keys are popular is that they are capable to fit into small compact spaces. Another reason is they can easily tighten and loosen hex screws by utilizing torque.
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