Extruded Sheet Metal Hole

The following illustration shows the extruded hole geometry.

Extruded sheet metal hole.

Applications include for self tapping sheet metal screws or in thicker material to permit tapping for machine screws. You can imagine the shape as being a body to the punch of any shape and from this protrudes the punch pin of the diameter you want. Extruded holes unipunch tooling can be used to simultaneously punch a hole and extrude the material down. If extruded holes are too close it can lead to metal deformation.

Alternately the hole could be pre pierced in a separate station and then the edges extruded at a second station. Certain distance should be maintained between two extruded holes in sheet metal designs. Tap fix screws for extruded holes in light gauge steel this article provides tap fix hole size recommendations for metals using light gauge punched extruded materials. Creating an extruded hole using a punching process requires extreme pressure force.

It is recommended that the minimum distance between two extruded holes should be six times the thickness of sheet metal. For the tapped screw hole this is typically made using a male punch that creates the hole and extrudes the metal.