Sheet Metal Bend Formulas
BA = (pi/180) x Angle x (R + K x T)
OSSB = tan(Angle/2) x (R + T)
BD = 2 x OSSB - BA
Flat Length = Leg A + Leg B + BA - 2 x OSSB (or Leg A + Leg B - BD)
K-Factor Guide
- Air bending: K = 0.33 (most common)
- Bottom bending: K = 0.42
- Coining: K = 0.50
- Thinner materials and larger radii tend toward lower K-factors