why we use y-factor in sheet metal
2 Answers

Generally, K - Factor is used to calculate the flat pattern or flat length of sheet metal.
K - factor is defined as the ratio between the material thickness (T) and the neutral fibre axis (t), i.e. the part of the material that bends without being compressed nor elongated.
K = t/T
Y - Factor is similar to K - factor. Y factor is a constant used to calculate sheet metal part developed length.
Y = k*pie/2