What is the purpose of an Allen wrench?

• A. A High Torque Wrench With Two Closed Ends.
• B. A Wrench With One Open And One Closed End.
• C. A Wrench With Ratchet Movement, Used With A Socket.
• D. A Tool Used To Tighten Or Loosen Allen Screws.

Answer: (D)

Allen wrenches are designed to drive screws that have an internal hexagonal socket. The hexagonal shape fits snugly into that recess, allowing you to apply torque without stripping the corners. The L-shaped design provides leverage and lets you reach into tight spaces, which is common for hex-socket fasteners. Other described tools are for different kinds of fasteners—external heads or sockets—not for hex socket screws—so they don’t serve the specific purpose of engaging Allen screws.