Final answer:
To create a back to back bend in conduit bending, the 'deduct' or 'back-to-back' mark on the bender is utilized to compensate for the length of conduit flattened during the bend, maintaining accurate distance between bends.
Step-by-step explanation:
When performing a back to back bend in conduit bending, a special mark on the bender called the 'deduct' or 'back-to-back' mark is used. This mark accounts for the length of the conduit that will be flattened during the bending process, ensuring that the length between bends remains accurate. The mark is crucial for precision in the alignment of conduits, especially when constructing electrical systems where conduits must be aligned properly to fit within an installation. Therefore, to make a back to back bend, you'd align the bending point with the 'deduct' or 'back-to-back' mark on your bender. It's important to understand that this process may vary slightly depending on the manufacturer of the conduit bender, but the general concept remains consistent across tools.