# Bend Deduction

Written by Jerry Ratzlaff on . Posted in Structural Engineering

Bend deduction, abbreviated as BA, is the amount of material needed to be removed to achieve the correct length.

## Bend deduction formula

 $$\large{ BD = 2 \; \left( r \;+\; t \right) \; tan \; \left( \frac{\theta}{2} \;-\; BA \right) }$$

### Where:

 Units English Metric $$\large{ BD }$$ = bend deduction $$\large{in}$$ $$\large{mm}$$ $$\large{ BA }$$ = bend allowance $$\large{in}$$ $$\large{mm}$$ $$\large{ \theta }$$ (Greek symbol theta) = bend angle $$\large{deg}$$ $$\large{rad}$$ $$\large{ r }$$ = inside radius $$\large{in}$$ $$\large{mm}$$ $$\large{ t }$$ = material thickness $$\large{in}$$ $$\large{mm}$$