Allen Wrenches, or hex keys as they are commonly called, have been around since the mid 1800s but were made into the common wrench you see today by Allen Manufacturing Company out of Connecticut in the early 1900s. Allen Wrench is the six-sided L-shaped wrench used to drive hexagon recessed socket screws.
Quick history on Allen Wrenches (Hex Keys) with common uses, benefits and specifications.
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