Hex Wrench (Allen)
An L-shaped hexagonal bar that drives hex-socket screws, sold in sets by size.
What is it?
The hex wrench, or Allen wrench, is an L-shaped hexagonal steel bar that fits hex-socket screws. The short end provides torque, the long end provides reach.
What is it used for?
- Driving hex-socket screws
- Assembling furniture and equipment
- Machinery and bicycle repair
How to choose
A set with both SAE and metric covers most work. Ball-end wrenches reach at an angle; standard ends are stronger.
Anatomy
Understanding the parts of a hex wrench (allen) helps you use, maintain, and buy it with confidence.
- Body: the main working portion of the tool
- Working end: the part that contacts the material
- Handle: the part you grip for control and leverage
Materials & construction
Quality hex wrench (allen)s are made from hardened, heat-treated steel (often chrome-vanadium or high-carbon) chosen for strength, edge retention, and resistance to wear and corrosion.
Safety & maintenance
- Inspect the tool before use and replace any that are worn or damaged
- Use the right tool for the job and apply controlled force
- Store tools clean and dry to prevent corrosion
- Wear appropriate eye protection for the work
Also known as
Allen wrench, Allen key, hex key