Which type of wrench has open jaws?

Open-end wrenches are specifically designed with two jaws at one end that can grasp the nut or bolt head's flat sides. This design allows for fast and easy access to fasteners in tight spaces, where a full encasing of the bolt might not be possible. The open jaws enable the wrench to be applied from different angles, which provides greater flexibility when working on various hardware. This wrench type is particularly useful for quick adjustments or loosening tight fasteners because it can be easily repositioned and used in succession without needing to remove it completely.

The other types of wrenches do not have an open design. Box wrenches feature a closed end that fits over the fastener, providing more stability but limiting access. Socket wrenches also have a closed design that accepts interchangeable sockets, allowing for a range of sizes to be used, but they are not open at the end. Torque wrenches, designed specifically for applying a specific amount of torque, usually involve a socket or closed design as well. Thus, open-end wrenches stand out because of their unique operational design characterized by the open jaws.