Definition
A hand wrench with an open-end jaw on one end and a closed box-end (ring) on the other, both sized to fit the same nut or bolt head. The open end allows quick engagement from the side, while the box end provides a stronger, slip-resistant grip for final tightening or initial loosening.
Plain English
A wrench with two different heads of the same size — one shaped like an open U, and one shaped like a closed ring. You use whichever end works best for the job.
Context Anchor
Seen in aircraft maintenance, owner-performed maintenance, and tool lists when selecting the right hand tool for nuts and bolts.
Derivation
Called 'combination' because it combines the two most common wrench styles — open-end and box-end — into a single tool, with both ends sized identically.
Why Pilots Care
Proper use prevents rounding of bolt heads and ensures aircraft fasteners remain securely torqued, supporting airworthiness.
Intuition Check
Do not confuse a combination wrench with an adjustable wrench. A combination wrench is normally one fixed size; it just has two different working ends.
Example Sentence 1
The mechanic used the box end of the combination wrench to break the nut loose, then switched to the open end to spin it off quickly.
Example Sentence 2
During the preflight, she used the open end of her combination wrench to break the nut loose before switching to the box end for final torque.