Form down last
When using forming tools, form down operations are generally avoided because they take up so much vertical room and any additional operations tend to flatten them out or bend the sheet. They can also drop into dies, get caught and pull out of work holders. However, if a form down operation is the only solution for a particular piece part, make it the last operation on the sheet.


How to punch large holes without exceeding press tonnage
Although tooling is available for round holes up to station maximums for the largest station, such holes can exceed press capacities, especially in high shear strength materials. Creating the hole with more than one hit may solve the problem. Using smaller tools to break long perimeters on large tools can cut tonnage by a half or more, without resorting to nibbling the entire periphery. The diagrams above use rounds, double D’s, a quad radius and a biconvex radius. In all three, slugs fall away through the die, leaving no scrap on the punch press table.


Recommended minimum distance between holes, between forms and from edges of sheets.
If holes and forms are placed any closer to each other or to edges of sheets than is given below, they may distort each other or the material.
Minimum 2 times material thickness between holes.
Minimum 2 _ times material thickness between
hole and edge of sheet.
Minimum 3 times material thickness from form to edge of sheet.
Minimum 6 times material thickness between forms.


Recommended die penetration is .118”(3.0mm).

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