(also allen wrench)Trademark ; US
An L-shaped metal bar with a hexagonal head at each end, used to turn bolts and screws having hexagonal sockets.British term Allen key
Allen wrench/ˈalən ˌrenCH/ /ˈælən ˌrɛntʃ/
Early 20th century from the name of the manufacturer, the Allen Manufacturing Company, of Hartford, Connecticut.
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