Center of extruded holes a 5 hole dia 2t extruded hole and bend edge c 3t r d 2.
Extruded hole in sheet metal.
Extruded hole to part edge b 3t d 2.
Unipunch tooling can be used to simultaneously punch a hole and extrude the material down.
For a hole 1 in diameter the minimum distance d 2t r see fig.
Therefore the minimum distance between the extruded hole to edge if maintained.
Extrude tite screws were designed to resolve the fastening problems of stripping and spin out in thin sheet metal found when using standard round bodied sheet metal screws.
Certain distance should be maintained between two extruded holes in sheet metal designs.
The minimum distance from an extruded hole to a bend is three times the material thickness plus the bend radius.
An extruded hole is one that is generated at one station using a specially stepped punch that first shears a smaller hole and then follows through to deform the local area around the hole into a projection by limited forward extrusion.
Extrusions our commonly used to accept sheet metal screws or permit tapping into a deeper distance than just the material thickness.
The diameter of the pre punched hole ultimately determines the height of the extrusion.
If extruded holes are too close it can lead to metal deformation.
It is recommended that the minimum distance between two extruded holes should be six times the thickness of sheet metal.
B for a slot or hole 1 diameter then the minimum distance d 2 5t r see fig.
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.
Increased torque performance in thin sheet metal applications.
Alternately the hole could be pre pierced in a separate station and then the edges extruded at a second station.
The following illustration shows the extruded hole geometry.
The minimum distance from an extruded hole to an edge is three times the material thickness.
The extrusion punch should be made of highly wear resistant tool steel powdered metal pm preferably or solid carbide material.
The punch should be polished linearly to a mirrorlike surface finish.
Extruded holes very close to the part edge can lead to sheet metal deformation or tearing.
The minimum distance between two extruded holes is six times the material thickness.
A legacy product extrude tite screws have been now largely superceded by fastite 2000 fasteners.
A pre punched hole is required as a one hit pierce and extrude gives poor hole quality and has limited adjustment on the machine.
Relieve the punch after extruding the straight section to allow for lubricant to settle into the negative portion of the punch.
