Which tool is specifically designed for working with 45° elbows?

The plumber's rule is specifically designed to assist in accurately measuring and cutting pipe sections for fittings, including 45° elbows. When working with plumbing, ensuring the correct angle and measurement is crucial for proper fit and alignment. The plumber's rule often has markings that correspond directly to common angles used in plumbing applications, allowing for precise adjustments when cutting or fitting pipe.

Using this tool helps in determining the right length for the pipe segments that will connect with the 45° elbows, ensuring a seamless transition and efficient flow within the system. Although levels, squares, and protractors are useful tools in various aspects of plumbing and construction, they do not provide the same specific guidance tailored to the unique requirements of fitting 45° elbows in pipework. Levels are typically used to check the horizontal or vertical plane, squares are used for checking right angles, and protractors help measure angles but lack the practical application specific to the plumbing context that a plumber's rule offers.