Definition of Allen bolt
: a bolt with a hexagonal socket in its head that is designed to be used with an Allen wrench The Allen bolt is integral to the crank and remains in it when the crank is removed from the spindle. — Eugene A. Sloane, Sloane’s New Bicycle Maintenance Manual, 1981
Love words? You must — there are over 200,000 words in our free online dictionary, but you are looking for one that’s only in the Merriam-Webster Unabridged Dictionary.
Start your free trial today and get unlimited access to America's largest dictionary, with:
- More than 250,000 words that aren't in our free dictionary
- Expanded definitions, etymologies, and usage notes
- Advanced search features
- Ad free!
Origin and Etymology of allen bolt
Allen Manufacturing Co., Hartford, Connecticut
First Known Use: 1972See Words from the same year
Seen and Heard
What made you want to look up Allen bolt? Please tell us where you read or heard it (including the quote, if possible).