Box forming requires a high male punch and a low female die, and the forming should be done in 90° die. The average machine has a 12 inch die space, and with the die mounted directly on the bed, is capable of forming a box approximately 6½ deep.
When a box deeper that 6½" must be formed, a 90° die machined on a 60°-30° angle may be used on a 16 GA material and lighter. However, this is not looked upon favorably as a means of producing boxes because of difficulty encountered in gauging the bends.
A set of dies so machined will produce a approximately 7¼" deep.
If boxes having a depth greater than 7¼" must be formed, the machine must have a shut height or die space greater than standard. For each inch of added shut height, approximately 5/8" may be added to the depth of the box.
NOTE: In forming a box, where four sides are bent up. The punch must be high enough so that when making the last two bends, the preformed sides do not strike the ram.
Punch Height for Box Forming (for ram thickness=2½")