Which feature is true about an Allen wrench?

Which feature is true about an Allen wrench?

• A. It has a hex or six-sided recess in the head, and ends are the same size.
• B. It has a square recess in the head and different end sizes.
• C. It is used for cutting hex screws.
• D. It is designed for metric-only fasteners.

Answer: (A)

An Allen wrench is a hex key: a small L-shaped tool designed to drive screws that have a hexagonal socket. Its defining feature is the hexagonal cross-section, which fits snugly into the corresponding hex recess in the screw head, allowing you to apply torque without slipping. Because both ends share the same hex size, either end can be used for the same screw size—the longer leg just provides more leverage while the hex fit remains the same. Allen wrenches come in both metric and SAE sizes, so they’re not limited to metric-only fasteners. They’re not used for cutting screws, and the idea of a square recess or a non-hex drive describes a different type of fastener.

An Allen wrench is a hex key: a small L-shaped tool designed to drive screws that have a hexagonal socket. Its defining feature is the hexagonal cross-section, which fits snugly into the corresponding hex recess in the screw head, allowing you to apply torque without slipping. Because both ends share the same hex size, either end can be used for the same screw size—the longer leg just provides more leverage while the hex fit remains the same. Allen wrenches come in both metric and SAE sizes, so they’re not limited to metric-only fasteners. They’re not used for cutting screws, and the idea of a square recess or a non-hex drive describes a different type of fastener.