Studying for this portion of the CSWP test is mostly conceptual. The options available here are only have subtle differences but in manufacture they can have a significant impact.
Bend Allowance:
Using a bend allowance the flat part will be longer than the distance of each flange combined.
Bend Deduction:
Using a bend deduction the flat part will be shorter than the distance of each flange combined.
K-Factor:
This is a slightly more involved calculation that is defined by how a material deforms. A bend creates two types of stress on a material. Compression on the inside of the curve (creating a shorter inside distance) and tension on the outside of the curve (where the material is stretched longer than it’s original).
Gauge Tables: Gauge Bend tables are one way to define bend values. A little up front leg work in setting these up can save a lot of hassle and many small errors. Because values are unique to the material a separate table is required for each material.