Adopt Delta Servo motor control, movement is accurate, torsion is strong, bending coefficient database is exquisite, one-step molding.

The computation expression for the strain neutral layer of stress and plastic bending was introduced and so the thinning coefficient computing formula of sheet metal was deduced.

The results show that: the springback Angle of bent tube increases with the bending Angle, the gap between mandrel and tube, and the hardening coefficient, but decreases with the hardenability value.