What type of wrench operates between obstructions where space for handle swing is limited?

The box end wrench is specifically designed to fit over a nut or bolt and provides a secure grip due to its closed-end design. This feature allows it to be used effectively in confined spaces where the full swing of a handle isn't possible. The design allows the wrench to engage with the fastener more deeply, which is beneficial when working in tight areas, as it minimizes the risk of slipping and ensures a tighter grip compared to other wrench types. Its structure is ideal for reaching fasteners that may be obstructed by other components, making it a valuable tool in both aviation maintenance and other mechanical applications.

In contrast, the other types of wrenches may require greater space for handle movement or might not fit securely over fasteners in tight spaces. The adjustable wrench, for example, has a movable jaw that can modify its size but often requires more space to operate effectively. The open wrench provides a slim profile but lacks the containment of the fastener that a box end offers, leading to potential slipping under load. The socket wrench is also designed to work well in tight areas, but it typically requires a ratchet handle, which might need additional space compared to a box end wrench.