A box‑end wrench has a closed loop with internal notches. Depending on its points, it fits square or hexagonal nuts or both.
Typical applications
- Box-end wrenches fit over the matching nut or bolt. The number of points affects which fastener shapes fit.
Advantages
- A box‑end wrench has a closed notched loop; an open‑end wrench has parallel open jaws. Choose the type that fits the job.
Specifications to check
- When selecting a box‑end wrench, check the size and point configuration against the fastener. Do not assume every box‑end wrench fits both square and hexagonal shapes.
Limitations
- A generic box‑end wrench should not be used on moving machinery, and its handle should not be extended with a pipe for extra leverage.
Buying considerations
When buying a generic box‑end wrench, discard any with broken or damaged points. Select the correct wrench type and size for the job.
Safety & limits
- When using a box‑end wrench, wear eye protection if flying particles or falling debris are a hazard. A face shield must be worn in addition to safety glasses or goggles.
Sources & further reading
These links document the information used in this article. Manufacturer specifications and source research are not hands-on test results or an endorsement of a purchase.
- CCOHS: Box-end wrench
Reference checked 2026-10-29