Rule of Thumb formula for making multiple bends on a press brake.  For shape shown, in mild steel with radii equal to metal thickness unless otherwise noted.

Tonnagechart.pdf

Shape	Description	Airform	Bottoming
	Vee Die	60	150
	Wiping	–	250
	Offset	150	300/600
	MTL.THK Offset	300	600
	Channel	225	300
	Vee Rib	200	600
	W Die	300	600
	Open Hat Channel	300	450
	Sq. Hat Channel	–	600
	Perform Curl	–	300
	Perform Curl	–	200
	Close Curl	–	300
	Radius	–	180/300
Shape Considerations		Large Radi Angle Variation Concave or Convex Slides	Material Thk. Radi Min. Angle Variation Maintain Flatness

Multiply Metal Thickness by factor = Tons per Foot