an L-shaped tool consisting of a rod having a hexagonal cross section, used to turn a screw (Allen screw) with a hexagonal recess in the head. A different size of key is required for each size of screw
Examples of 'hex key' in a sentence
hex key
They include a 41-piece socket set, 24 combination spanners, adjustable and hex-key wrenches and a 100-piece bit set.