onnage for flaring
 

tonnage for flaring
i have a circular hole, in a sheetmetal part, with a 90 deg. flange all of the way around the circumference of the hole. i need to bring a press down and flare this flange to a 45 deg. angle all of the way around the circumference. can anyone tell me how to calculate the required tonnage for this type of bend? the flared flange will not be supported on the back side. thanks for your help!