1. The distance from the edge of a pierced hole to the edge of the part, should not be less than the material thickness.

2. When the distance from the hole to the edge is less than the metal thickness it can result in a bulge.

3. When the hole is extremely close to the edge it may cause the metal to break-out.

4. One method of eliminating an edge bulge would be to blank a slot in place of a hole.

5. A second alternative would be to design a small ear on the outside of the part (if space permits).

6. A third alternative where a hole needs to be on the edge, or outside the edge of the part, is to design an extended ear, allowing a minimum of metal thickness all around the hole.