Pronunciation: [hɛksˈaɡənə͡l kˈiː] (IPA) 
The correct spelling for the tool commonly known as a "hex key" or "Allen wrench" is "hexagonal key." This term refers to a tool with a six-sided shape that is designed to fit into hexagonal sockets or recesses in bolts or screws. The phonetic transcription for "hexagonal key" is /hɛkˈsæɡənəl ki/. The word is divided into syllables as hex-a-go-nal key, with primary stress on the second syllable "a."
A hexagonal key, also known as an Allen wrench, is a small handheld tool used for turning bolts and screws with hexagonal or six-sided recessed heads. The tool features a short, L-shaped design, with one end containing a hexagonal-shaped tip and the other end having a handle or grip. Hexagonal keys are typically made of durable steel or other strong materials.
The hexagonal tip of the key is inserted into the recessed head of a bolt or screw, allowing the user to apply torque or rotational force to tighten or loosen it. The six-sided shape provides a secure and precise fit, preventing slippage and ensuring effective turning without damaging the fastener. Depending on their size, hexagonal keys are available with different diameter tips to fit various hexagonal head sizes.
Hexagonal keys are commonly used in various industries, particularly in automotive, manufacturing, construction, and DIY projects. They are especially favored for their compact size, versatility, and ability to access tight or recessed spaces where a wrench or a screwdriver may not fit.
Given their frequent use, hexagonal keys are often found in toolkits and are essential for assembling furniture, bikes, machinery, electronics, and a range of other applications. They are a cost-effective and efficient tool that simplifies the process of fastening and loosening hexagonal screws and bolts in a precise and controlled manner.
The word "hexagonal key" is a combination of two terms with distinct origins.
1. Hexagonal: The term "hexagonal" comes from the Greek word "hexagonon", which means "six-angled" or "six-sided". This, in turn, is derived from the Greek words "hex" meaning "six" and "gonia" meaning "angle". The prefix "hexa-" is commonly used in English to denote something related to six.
2. Key: The term "key" in this context refers to a tool used for turning or tightening screws and bolts with corresponding sockets or holes. The word "key" dates back to Middle English, originating from the Old English word "cǣg", which means "metal instrument" or "metal piece". It is believed to be derived from the Proto-Germanic word "kaigaz".
